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Economics () is the social science that studies the production, distribution, and consumption of goods and services. Economics focuses on the behaviour and interactions of
economic agents In economics, an agent is an actor (more specifically, a decision maker) in a model of some aspect of the economy. Typically, every agent makes decisions by solving a well- or ill-defined optimization or choice problem. For example, ''buyers'' (c ...
and how economies work. Microeconomics analyzes what's viewed as basic elements in the economy, including individual agents and markets, their interactions, and the outcomes of interactions. Individual agents may include, for example, households, firms, buyers, and sellers.
Macroeconomics Macroeconomics (from the Greek prefix ''makro-'' meaning "large" + ''economics'') is a branch of economics dealing with performance, structure, behavior, and decision-making of an economy as a whole. For example, using interest rates, taxes, and ...
analyzes the economy as a system where production, consumption, saving, and investment interact, and factors affecting it: employment of the resources of labour, capital, and land, currency inflation,
economic growth Economic growth can be defined as the increase or improvement in the inflation-adjusted market value of the goods and services produced by an economy in a financial year. Statisticians conventionally measure such growth as the percent rate of ...
, and public policies that have impact on these elements. Other broad distinctions within economics include those between positive economics, describing "what is", and normative economics, advocating "what ought to be"; between economic theory and applied economics; between rational and behavioural economics; and between
mainstream economics Mainstream economics is the body of knowledge, theories, and models of economics, as taught by universities worldwide, that are generally accepted by economists as a basis for discussion. Also known as orthodox economics, it can be contrasted to h ...
and
heterodox economics Heterodox economics is any economic thought or theory that contrasts with orthodox schools of economic thought, or that may be beyond neoclassical economics.Frederic S. Lee, 2008. "heterodox economics," ''The New Palgrave Dictionary of Economics' ...
. Economic analysis can be applied throughout society, including
business Business is the practice of making one's living or making money by producing or Trade, buying and selling Product (business), products (such as goods and Service (economics), services). It is also "any activity or enterprise entered into for pr ...
,
finance Finance is the study and discipline of money, currency and capital assets. It is related to, but not synonymous with economics, the study of production, distribution, and consumption of money, assets, goods and services (the discipline of fina ...
,
health care Health care or healthcare is the improvement of health via the prevention, diagnosis, treatment, amelioration or cure of disease, illness, injury, and other physical and mental impairments in people. Health care is delivered by health profe ...
, engineering and government. It is also applied to such diverse subjects as crime, education, the family, feminism, law,
philosophy Philosophy (from , ) is the systematized study of general and fundamental questions, such as those about existence, reason, knowledge, values, mind, and language. Such questions are often posed as problems to be studied or resolved. Some ...
, politics, religion, social institutions, war, science, and the environment.


Definitions of economics over time

The earlier term for the discipline was ' political economy', but since the late 19th century, it has commonly been called 'economics'. The term is derived from the Ancient Greek (''oikonomikos''), "practiced in the management of a household or family" and therefore "frugal, thrifty", which in turn comes from (''oikonomia'') "household management" which in turn comes from (' "house") and (', "custom" or "law"). There are a variety of modern definitions of economics; some reflect evolving views of the subject or different views among economists.
Scottish Scottish usually refers to something of, from, or related to Scotland, including: *Scottish Gaelic, a Celtic Goidelic language of the Indo-European language family native to Scotland *Scottish English *Scottish national identity, the Scottish ide ...
philosopher
Adam Smith Adam Smith (baptized 1723 – 17 July 1790) was a Scottish economist and philosopher who was a pioneer in the thinking of political economy and key figure during the Scottish Enlightenment. Seen by some as "The Father of Economics"——— ...
(1776) defined what was then called political economy as "an inquiry into the nature and causes of the wealth of nations", in particular as:
Jean-Baptiste Say Jean-Baptiste Say (; 5 January 1767 – 15 November 1832) was a liberal French economist and businessman who argued in favor of competition, free trade and lifting restraints on business. He is best known for Say's law—also known as the law of ...
(1803), distinguishing the subject from its public-policy uses, defined it as the science ''of'' production, distribution, and consumption of wealth. On the
satirical Satire is a genre of the visual, literary, and performing arts, usually in the form of fiction and less frequently non-fiction, in which vices, follies, abuses, and shortcomings are held up to ridicule, often with the intent of shaming or e ...
side, Thomas Carlyle (1849) coined " the dismal science" as an
epithet An epithet (, ), also byname, is a descriptive term (word or phrase) known for accompanying or occurring in place of a name and having entered common usage. It has various shades of meaning when applied to seemingly real or fictitious people, di ...
for
classical economics Classical economics, classical political economy, or Smithian economics is a school of thought in political economy that flourished, primarily in Britain, in the late 18th and early-to-mid 19th century. Its main thinkers are held to be Adam Smith ...
, in this context, commonly linked to the pessimistic analysis of
Malthus Thomas Robert Malthus (; 13/14 February 1766 – 29 December 1834) was an English cleric, scholar and influential economist in the fields of political economy and demography. In his 1798 book ''An Essay on the Principle of Population'', Malt ...
(1798).
John Stuart Mill John Stuart Mill (20 May 1806 – 7 May 1873) was an English philosopher, political economist, Member of Parliament (MP) and civil servant. One of the most influential thinkers in the history of classical liberalism, he contributed widely to ...
(1844) defined the subject in a social context as:
Alfred Marshall Alfred Marshall (26 July 1842 – 13 July 1924) was an English economist, and was one of the most influential economists of his time. His book '' Principles of Economics'' (1890) was the dominant economic textbook in England for many years. I ...
provided a still widely cited definition in his textbook '' Principles of Economics'' (1890) that extended analysis beyond wealth and from the
societal A society is a group of individuals involved in persistent social interaction, or a large social group sharing the same spatial or social territory, typically subject to the same political authority and dominant cultural expectations. Societ ...
to the
microeconomic Microeconomics is a branch of mainstream economics that studies the behavior of individuals and firms in making decisions regarding the allocation of scarce resources and the interactions among these individuals and firms. Microeconomics fo ...
level: Lionel Robbins (1932) developed implications of what has been termed " rhaps the most commonly accepted current definition of the subject": Robbins described the definition as not ''classificatory'' in "pick ngout certain ''kinds'' of behaviour" but rather ''analytical'' in "focus ngattention on a particular ''aspect'' of behaviour, the form imposed by the influence of scarcity." He affirmed that previous economists have usually centred their studies on the analysis of wealth: how wealth is created (production), distributed, and consumed; and how wealth can grow. But he said that economics can be used to study other things, such as war, that are outside its usual focus. This is because war has as the goal winning it (as a sought after end), generates both cost and benefits; and, resources (human life and other costs) are used to attain the goal. If the war is not winnable or if the expected costs outweigh the benefits, the deciding actors (assuming they are rational) may never go to war (a decision) but rather explore other alternatives. We cannot define economics as the science that studies wealth, war, crime, education, and any other field economic analysis can be applied to; but, as the science that studies a particular common aspect of each of those subjects (they all use scarce resources to attain a sought after end). Some subsequent comments criticized the definition as overly broad in failing to limit its subject matter to analysis of markets. From the 1960s, however, such comments abated as the economic theory of maximizing behaviour and rational-choice modelling expanded the domain of the subject to areas previously treated in other fields. There are other criticisms as well, such as in scarcity not accounting for the
macroeconomics Macroeconomics (from the Greek prefix ''makro-'' meaning "large" + ''economics'') is a branch of economics dealing with performance, structure, behavior, and decision-making of an economy as a whole. For example, using interest rates, taxes, and ...
of high unemployment. Gary Becker, a contributor to the expansion of economics into new areas, described the approach he favoured as "combin ng theassumptions of maximizing behaviour, stable preferences, and market equilibrium, used relentlessly and unflinchingly." One commentary characterizes the remark as making economics an approach rather than a subject matter but with great specificity as to the "choice process and the type of
social interaction A social relation or also described as a social interaction or social experience is the fundamental unit of analysis within the social sciences, and describes any voluntary or involuntary interpersonal relationship between two or more individuals ...
that uchanalysis involves." The same source reviews a range of definitions included in principles of economics textbooks and concludes that the lack of agreement need not affect the subject-matter that the texts treat. Among economists more generally, it argues that a particular definition presented may reflect the direction toward which the author believes economics is evolving, or should evolve. According to economist Ha-Joon Chang economics should be defined not in terms of its methodology or theoretical approach but in terms of its subject matter. Ha-Joon Chang finds a definition like "the science which studies human behavior as a relationship between ends and scarce means which have alternative uses" very peculiar because all other sciences define themselves in terms of the area of inquiry or object of inquiry rather than the methodology. In the biology department, they don't say that all biology should be studied with DNA analysis. People study living organisms in many different ways, so some people will do DNA analysis, others might do anatomy, and still others might build game theoretic models of animal behavior. But they are all called biology because they all study living organisms. According to Ha Joon Chang, this view that you can and should study the economy in only one way (for example by studying only rational choices), and going even one step further and basically redefining economics as a theory of everything, is very peculiar.


History of economic thought


From antiquity through the physiocrats

Questions regarding distribution of resources are found throughout the writings of the
Boeotian Boeotia ( ), sometimes Latinized as Boiotia or Beotia ( el, Βοιωτία; modern: ; ancient: ), formerly known as Cadmeis, is one of the regional units of Greece. It is part of the region of Central Greece. Its capital is Livadeia, and its lar ...
poet
Hesiod Hesiod (; grc-gre, Ἡσίοδος ''Hēsíodos'') was an ancient Greek poet generally thought to have been active between 750 and 650 BC, around the same time as Homer. He is generally regarded by western authors as 'the first written poet i ...
and several economic historians have described Hesiod himself as the "first economist". However, the word Oikos, the Greek word from which the word economy derives, was used for issues regarding how to manage a household (which was understood to be the landowner, his family, and his slaves) rather than to refer to some normative societal system of distribution of resources, which is a much more recent phenomenon. Xenophon, the author of the Oeconomicus, is credited by philologues for being the source of the word economy. Other notable writers from
Antiquity Antiquity or Antiquities may refer to: Historical objects or periods Artifacts *Antiquities, objects or artifacts surviving from ancient cultures Eras Any period before the European Middle Ages (5th to 15th centuries) but still within the histo ...
through to the Renaissance which wrote on include Aristotle, Chanakya (also known as Kautilya), Qin Shi Huang,
Ibn Khaldun Ibn Khaldun (; ar, أبو زيد عبد الرحمن بن محمد بن خلدون الحضرمي, ; 27 May 1332 – 17 March 1406, 732-808 AH) was an Arab The Historical Muhammad', Irving M. Zeitlin, (Polity Press, 2007), p. 21; "It is, of ...
, and Thomas Aquinas. Joseph Schumpeter described 16th and 17th century
scholastic Scholastic may refer to: * a philosopher or theologian in the tradition of scholasticism * ''Scholastic'' (Notre Dame publication) * Scholastic Corporation, an American publishing company of educational materials * Scholastic Building, in New Y ...
writers, including Tomás de Mercado, Luis de Molina, and Juan de Lugo, as "coming nearer than any other group to being the 'founders' of scientific economics" as to monetary, interest, and value theory within a natural-law perspective. Two groups, who later were called "mercantilists" and "physiocrats", more directly influenced the subsequent development of the subject. Both groups were associated with the rise of economic nationalism and modern capitalism in Europe.
Mercantilism Mercantilism is an economic policy that is designed to maximize the exports and minimize the imports for an economy. It promotes imperialism, colonialism, tariffs and subsidies on traded goods to achieve that goal. The policy aims to reduce a ...
was an economic doctrine that flourished from the 16th to 18th century in a prolific pamphlet literature, whether of merchants or statesmen. It held that a nation's wealth depended on its accumulation of gold and silver. Nations without access to mines could obtain gold and silver from trade only by selling goods abroad and restricting imports other than of gold and silver. The doctrine called for importing cheap raw materials to be used in manufacturing goods, which could be exported, and for state regulation to impose protective tariffs on foreign manufactured goods and prohibit manufacturing in the colonies. Physiocrats, a group of 18th-century French thinkers and writers, developed the idea of the economy as a circular flow of income and output. Physiocrats believed that only agricultural production generated a clear surplus over cost, so that agriculture was the basis of all wealth. Thus, they opposed the mercantilist policy of promoting manufacturing and trade at the expense of agriculture, including import tariffs. Physiocrats advocated replacing administratively costly tax collections with a single tax on income of land owners. In reaction against copious mercantilist trade regulations, the physiocrats advocated a policy of '' laissez-faire'', which called for minimal government intervention in the economy.
Adam Smith Adam Smith (baptized 1723 – 17 July 1790) was a Scottish economist and philosopher who was a pioneer in the thinking of political economy and key figure during the Scottish Enlightenment. Seen by some as "The Father of Economics"——— ...
(1723–1790) was an early economic theorist. Smith was harshly critical of the mercantilists but described the physiocratic system "with all its imperfections" as "perhaps the purest approximation to the truth that has yet been published" on the subject.


Classical political economy

The publication of Adam Smith's '' The Wealth of Nations'' in 1776, has been described as "the effective birth of economics as a separate discipline." The book identified land, labour, and capital as the three factors of production and the major contributors to a nation's wealth, as distinct from the physiocratic idea that only agriculture was productive. Smith discusses potential benefits of specialization by
division of labour The division of labour is the separation of the tasks in any economic system or organisation so that participants may specialise (specialisation). Individuals, organizations, and nations are endowed with, or acquire specialised capabilities, and ...
, including increased labour productivity and
gains from trade In economics, gains from trade are the net benefits to economic agents from being allowed an increase in voluntary trading with each other. In technical terms, they are the increase of consumer surplus plus producer surplus from lower tariffs ...
, whether between town and country or across countries. His "theorem" that "the division of labor is limited by the extent of the market" has been described as the "core of a theory of the functions of firm and industry" and a "fundamental principle of economic organization." To Smith has also been ascribed "the most important substantive proposition in all of economics" and foundation of resource-allocation theory – that, under competition, resource owners (of labour, land, and capital) seek their most profitable uses, resulting in an equal rate of return for all uses in equilibrium (adjusted for apparent differences arising from such factors as training and unemployment). In an argument that includes "one of the most famous passages in all economics," Smith represents every individual as trying to employ any capital they might command for their own advantage, not that of the society, and for the sake of profit, which is necessary at some level for employing capital in domestic industry, and positively related to the value of produce. In this: The
Rev. The Reverend is an honorific style most often placed before the names of Christian clergy and ministers. There are sometimes differences in the way the style is used in different countries and church traditions. ''The Reverend'' is correctly ...
Thomas Robert Malthus (1798) used the concept of diminishing returns to explain low living standards.
Human population Humans (''Homo sapiens'') are the most abundant and widespread species of primate, characterized by bipedalism and exceptional cognitive skills due to a large and complex brain. This has enabled the development of advanced tools, culture, ...
, he argued, tended to increase geometrically, outstripping the production of food, which increased arithmetically. The force of a rapidly growing population against a limited amount of land meant diminishing returns to labour. The result, he claimed, was chronically low wages, which prevented the standard of living for most of the population from rising above the subsistence level. Economist Julian Lincoln Simon has criticized Malthus's conclusions. While Adam Smith emphasized the production of income, David Ricardo (1817) focused on the distribution of income among landowners, workers, and capitalists. Ricardo saw an inherent conflict between landowners on the one hand and labour and capital on the other. He posited that the growth of population and capital, pressing against a fixed supply of land, pushes up rents and holds down wages and profits. Ricardo was the first to state and prove the principle of comparative advantage, according to which each country should specialize in producing and exporting goods in that it has a lower ''relative'' cost of production, rather relying only on its own production. It has been termed a "fundamental analytical explanation" for
gains from trade In economics, gains from trade are the net benefits to economic agents from being allowed an increase in voluntary trading with each other. In technical terms, they are the increase of consumer surplus plus producer surplus from lower tariffs ...
. Coming at the end of the classical tradition,
John Stuart Mill John Stuart Mill (20 May 1806 – 7 May 1873) was an English philosopher, political economist, Member of Parliament (MP) and civil servant. One of the most influential thinkers in the history of classical liberalism, he contributed widely to ...
(1848) parted company with the earlier classical economists on the inevitability of the distribution of income produced by the market system. Mill pointed to a distinct difference between the market's two roles: allocation of resources and distribution of income. The market might be efficient in allocating resources but not in distributing income, he wrote, making it necessary for society to intervene. Value theory was important in classical theory. Smith wrote that the "real price of every thing ... is the toil and trouble of acquiring it". Smith maintained that, with rent and profit, other costs besides wages also enter the price of a commodity. Other classical economists presented variations on Smith, termed the ' labour theory of value'. Classical economics focused on the tendency of any market economy to settle in a final stationary state made up of a constant stock of physical wealth (capital) and a constant population size.


Marxian economics

Marxist (later, Marxian) economics descends from classical economics and it derives from the work of Karl Marx. The first volume of Marx's major work, '' Das Kapital'', was published in German in 1867. In it, Marx focused on the labour theory of value and the
theory of surplus value In Marxian economics, surplus value is the difference between the amount raised through a sale of a product and the amount it cost to the owner of that product to manufacture it: i.e. the amount raised through sale of the product minus the cost ...
which, he believed, explained the exploitation of labour by capital. The labour theory of value held that the value of an exchanged commodity was determined by the labour that went into its production and the theory of surplus value demonstrated how the workers only got paid a proportion of the value their work had created. Marxian economics was further developed by Karl Kautsky (1854-1938)'s ''The Economic Doctrines of Karl Marx'' and '' The Class Struggle (Erfurt Program)'', Rudolf Hilferding's (1877-1941) ''
Finance Capital Rudolf Hilferding (10 August 1877 – 11 February 1941) was an Austrian-born Marxist economist, socialist theorist,International Institute of Social History, ''Rodolf Hilferding Papers''. http://www.iisg.nl/archives/en/files/h/10751012.php pol ...
'', Vladimir Lenin (1870-1924)'s '' The Development of Capitalism in Russia'' and '' Imperialism, the Highest Stage of Capitalism'', and
Rosa Luxemburg Rosa Luxemburg (; ; pl, Róża Luksemburg or ; 5 March 1871 – 15 January 1919) was a Polish and naturalised-German revolutionary socialist, Marxist philosopher and anti-war activist. Successively, she was a member of the Proletariat party, ...
(1871-1919)'s '' The Accumulation of Capital''.


Neoclassical economics

At the dawn as a social science, economics was defined and discussed at length as the study of production, distribution, and consumption of wealth by Jean-Baptiste Say in his ''Treatise on Political Economy or, The Production, Distribution, and Consumption of Wealth'' (1803). These three items are considered by the science only in relation to the increase or diminution of wealth, and not in reference to their processes of execution. Say's definition has prevailed up to our time, saved by substituting the word "wealth" for "goods and services" meaning that wealth may include non-material objects as well. One hundred and thirty years later, Lionel Robbins noticed that this definition no longer sufficed, because many economists were making theoretical and philosophical inroads in other areas of human activity. In his ''
Essay on the Nature and Significance of Economic Science Lionel Robbins' ''Essay'' (1932, 1935, 2nd ed., 158 pp.) sought to define more precisely economics as a science and to derive substantive implications. Analysis is relative to "accepted solutions of particular problems" based on best modern practi ...
'', he proposed a definition of economics as a study of a particular aspect of human behaviour, the one that falls under the influence of scarcity, which forces people to choose, allocate scarce resources to competing ends, and economize (seeking the greatest welfare while avoiding the wasting of scarce resources). For Robbins, the insufficiency was solved, and his definition allows us to proclaim, with an easy conscience, education economics, safety and security economics, health economics, war economics, and of course, production, distribution and consumption economics as valid subjects of the economic science." Citing Robbins: "Economics is the science which studies human behavior as a relationship between ends and scarce means which have alternative uses". After discussing it for decades, Robbins' definition became widely accepted by mainstream economists, and it has opened way into current textbooks. Although far from unanimous, most mainstream economists would accept some version of Robbins' definition, even though many have raised serious objections to the scope and method of economics, emanating from that definition. Due to the lack of strong consensus, and that production, distribution and consumption of goods and services is the prime area of study of economics, the old definition still stands in many quarters. A body of theory later termed "neoclassical economics" or "
marginalism Marginalism is a theory of economics that attempts to explain the discrepancy in the value of goods and services by reference to their secondary, or marginal, utility. It states that the reason why the price of diamonds is higher than that of wa ...
" formed from about 1870 to 1910. The term "economics" was popularized by such neoclassical economists as
Alfred Marshall Alfred Marshall (26 July 1842 – 13 July 1924) was an English economist, and was one of the most influential economists of his time. His book '' Principles of Economics'' (1890) was the dominant economic textbook in England for many years. I ...
and
Mary Paley Marshall Mary Marshall (née Paley; 24 October 1850 – 19 March 1944) was an economist who in 1874 had been one of the first women to take the Tripos examination at Cambridge University – although, as a woman, she had been excluded from receiving ...
as a concise synonym for "economic science" and a substitute for the earlier " political economy". This corresponded to the influence on the subject of mathematical methods used in the
natural science Natural science is one of the branches of science concerned with the description, understanding and prediction of natural phenomena, based on empirical evidence from observation and experimentation. Mechanisms such as peer review and repeatab ...
s. Neoclassical economics systematized
supply and demand In microeconomics, supply and demand is an economic model of price determination in a Market (economics), market. It postulates that, Ceteris paribus, holding all else equal, in a perfect competition, competitive market, the unit price for a ...
as joint determinants of price and quantity in market equilibrium, affecting both the allocation of output and the distribution of income. It dispensed with the labour theory of value inherited from classical economics in favour of a
marginal utility In economics, utility is the satisfaction or benefit derived by consuming a product. The marginal utility of a Goods (economics), good or Service (economics), service describes how much pleasure or satisfaction is gained by consumers as a result o ...
theory of value on the demand side and a more general theory of costs on the supply side. In the 20th century, neoclassical theorists moved away from an earlier notion suggesting that total utility for a society could be measured in favour of ordinal utility, which hypothesizes merely behaviour-based relations across persons. In
microeconomics Microeconomics is a branch of mainstream economics that studies the behavior of individuals and firms in making decisions regarding the allocation of scarce resources and the interactions among these individuals and firms. Microeconomics fo ...
, neoclassical economics represents incentives and costs as playing a pervasive role in shaping
decision making In psychology, decision-making (also spelled decision making and decisionmaking) is regarded as the cognitive process resulting in the selection of a belief or a course of action among several possible alternative options. It could be either rati ...
. An immediate example of this is the consumer theory of individual demand, which isolates how prices (as costs) and income affect quantity demanded. In
macroeconomics Macroeconomics (from the Greek prefix ''makro-'' meaning "large" + ''economics'') is a branch of economics dealing with performance, structure, behavior, and decision-making of an economy as a whole. For example, using interest rates, taxes, and ...
it is reflected in an early and lasting
neoclassical synthesis The neoclassical synthesis (NCS), neoclassical–Keynesian synthesis, or just neo-Keynesianism was a neoclassical economics academic movement and paradigm in economics that worked towards reconciling the macroeconomic thought of John Maynard Key ...
with Keynesian macroeconomics. Neoclassical economics is occasionally referred as ''orthodox economics'' whether by its critics or sympathizers. Modern
mainstream economics Mainstream economics is the body of knowledge, theories, and models of economics, as taught by universities worldwide, that are generally accepted by economists as a basis for discussion. Also known as orthodox economics, it can be contrasted to h ...
builds on neoclassical economics but with many refinements that either supplement or generalize earlier analysis, such as econometrics,
game theory Game theory is the study of mathematical models of strategic interactions among rational agents. Myerson, Roger B. (1991). ''Game Theory: Analysis of Conflict,'' Harvard University Press, p.&nbs1 Chapter-preview links, ppvii–xi It has appli ...
, analysis of market failure and imperfect competition, and the
neoclassical model Neoclassical economics is an approach to economics in which the production, consumption and valuation (pricing) of goods and services are observed as driven by the supply and demand model. According to this line of thought, the value of a good ...
of
economic growth Economic growth can be defined as the increase or improvement in the inflation-adjusted market value of the goods and services produced by an economy in a financial year. Statisticians conventionally measure such growth as the percent rate of ...
for analysing long-run variables affecting
national income A variety of measures of national income and output are used in economics to estimate total economic activity in a country or region, including gross domestic product (GDP), gross national product (GNP), net national income (NNI), and adjusted nati ...
. Neoclassical economics studies the behaviour of
individual An individual is that which exists as a distinct entity. Individuality (or self-hood) is the state or quality of being an individual; particularly (in the case of humans) of being a person unique from other people and possessing one's own Maslow ...
s, households, and organizations (called economic actors, players, or agents), when they manage or use
scarce In economics, scarcity "refers to the basic fact of life that there exists only a finite amount of human and nonhuman resources which the best technical knowledge is capable of using to produce only limited maximum amounts of each economic good ...
resources, which have alternative uses, to achieve desired ends. Agents are assumed to act rationally, have multiple desirable ends in sight, limited resources to obtain these ends, a set of stable preferences, a definite overall guiding objective, and the capability of making a choice. There exists an economic problem, subject to study by economic science, when a
decision Decision may refer to: Law and politics * Judgment (law), as the outcome of a legal case *Landmark decision, the outcome of a case that sets a legal precedent * ''Per curiam'' decision, by a court with multiple judges Books * ''Decision'' (nove ...
(choice) is made by one or more resource-controlling players to attain the best possible outcome under bounded rational conditions. In other words, resource-controlling agents maximize value subject to the constraints imposed by the information the agents have, their cognitive limitations, and the finite amount of time they have to make and execute a decision. Economic science centres on the activities of the economic agents that comprise society. They are the focus of economic analysis. An approach to understanding these processes, through the study of agent behaviour under scarcity, may go as follows: The continuous interplay (exchange or trade) done by economic actors in all markets sets the prices for all goods and services which, in turn, make the rational managing of scarce resources possible. At the same time, the decisions (choices) made by the same actors, while they are pursuing their own interest, determine the level of output (production), consumption, savings, and investment, in an economy, as well as the remuneration (distribution) paid to the owners of labour (in the form of wages), capital (in the form of profits) and land (in the form of rent). Each period, as if they were in a giant feedback system, economic players influence the pricing processes and the economy, and are in turn influenced by them until a steady state (equilibrium) of all variables involved is reached or until an external shock throws the system toward a new equilibrium point. Because of the autonomous actions of rational interacting agents, the economy is a complex adaptive system.


Keynesian economics

Keynesian economics derives from John Maynard Keynes, in particular his book '' The General Theory of Employment, Interest and Money'' (1936), which ushered in contemporary
macroeconomics Macroeconomics (from the Greek prefix ''makro-'' meaning "large" + ''economics'') is a branch of economics dealing with performance, structure, behavior, and decision-making of an economy as a whole. For example, using interest rates, taxes, and ...
as a distinct field. The book focused on determinants of national income in the short run when prices are relatively inflexible. Keynes attempted to explain in broad theoretical detail why high labour-market unemployment might not be self-correcting due to low " effective demand" and why even price flexibility and monetary policy might be unavailing. The term "revolutionary" has been applied to the book in its impact on economic analysis. Keynesian economics has two successors. Post-Keynesian economics also concentrates on macroeconomic rigidities and adjustment processes. Research on micro foundations for their models is represented as based on real-life practices rather than simple optimizing models. It is generally associated with the University of Cambridge and the work of Joan Robinson. New-Keynesian economics is also associated with developments in the Keynesian fashion. Within this group researchers tend to share with other economists the emphasis on models employing micro foundations and optimizing behaviour but with a narrower focus on standard Keynesian themes such as price and wage rigidity. These are usually made to be endogenous features of the models, rather than simply assumed as in older Keynesian-style ones.


Chicago school of economics

The Chicago School of economics is best known for its free market advocacy and
monetarist Monetarism is a school of thought in monetary economics that emphasizes the role of governments in controlling the amount of money in circulation. Monetarist theory asserts that variations in the money supply have major influences on national ...
ideas. According to Milton Friedman and monetarists, market economies are inherently stable if the money supply does not greatly expand or contract.
Ben Bernanke Ben Shalom Bernanke ( ; born December 13, 1953) is an American economist who served as the 14th chairman of the Federal Reserve from 2006 to 2014. After leaving the Fed, he was appointed a distinguished fellow at the Brookings Institution. Durin ...
, former Chairman of the Federal Reserve, is among the economists today generally accepting Friedman's analysis of the causes of the Great Depression. Milton Friedman effectively took many of the basic principles set forth by Adam Smith and the classical economists and modernized them. One example of this is his article in the 13 September 1970 issue of ''The New York Times Magazine'', in which he claims that the social responsibility of business should be "to use its resources and engage in activities designed to increase its profits ... (through) open and free competition without deception or fraud."


Austrian School of economics

The Austrian School emphasizes human action, property rights and the freedom to contract and transact to have a thriving and successful economy. It also emphasizes that the state should play an infinitesimally small role (if any role) in the regulation of economic activity between two transacting parties. A key component of Austrian economics is the principle of sound money. As Ludwig Von Mises, one of the most prominent 20th century Austrian economists, stated, "Ideologically it (sound money) belongs in the same class with political constitutions and bills of rights." Austrian economists assert that sound money prevents government actors from debasing the currency, disrupting the savings rate of the population and artificially distorting the economic choices of individual actors.


Other schools and approaches

Other well-known schools or trends of thought referring to a particular style of economics practised at and disseminated from well-defined groups of academicians that have become known worldwide, include the Freiburg School, the
School of Lausanne The Lausanne School of economics, sometimes referred to as the Mathematical School, refers to the neoclassical economics school of thought surrounding Léon Walras and Vilfredo Pareto. It is named after the University of Lausanne The Universit ...
, post-Keynesian economics and the Stockholm school. Contemporary
mainstream economics Mainstream economics is the body of knowledge, theories, and models of economics, as taught by universities worldwide, that are generally accepted by economists as a basis for discussion. Also known as orthodox economics, it can be contrasted to h ...
is sometimes separated into the Saltwater approach of those universities along the Eastern and Western coasts of the US, and the Freshwater, or Chicago-school approach. Within macroeconomics there is, in general order of their historical appearance in the literature;
classical economics Classical economics, classical political economy, or Smithian economics is a school of thought in political economy that flourished, primarily in Britain, in the late 18th and early-to-mid 19th century. Its main thinkers are held to be Adam Smith ...
, neoclassical economics, Keynesian economics, the neoclassical synthesis, monetarism, new classical economics, New Keynesian economics and the new neoclassical synthesis. In general, alternative developments include ecological economics, constitutional economics,
institutional economics Institutional economics focuses on understanding the role of the Sociocultural evolution, evolutionary process and the role of institutions in shaping Economy, economic Human behavior, behavior. Its original focus lay in Thorstein Veblen's instin ...
, evolutionary economics, dependency theory, structuralist economics,
world systems theory World-systems theory (also known as world-systems analysis or the world-systems perspective)Immanuel Wallerstein, (2004), "World-systems Analysis." In ''World System History'', ed. George Modelski, in ''Encyclopedia of Life Support Systems'' (E ...
, econophysics, econodynamics, feminist economics and
biophysical economics Thermoeconomics, also referred to as biophysical economics, is a school of heterodox economics that applies the laws of statistical mechanics to economic theory. Thermoeconomics can be thought of as the statistical physics of economic value and ...
.


Methodology


Theoretical research

Mainstream economic theory relies upon '' a priori'' quantitative economic models, which employ a variety of concepts. Theory typically proceeds with an assumption of ''
ceteris paribus ' (also spelled '; () is a Latin phrase, meaning "other things equal"; some other English translations of the phrase are "all other things being equal", "other things held constant", "all else unchanged", and "all else being equal". A statement ...
'', which means holding constant explanatory variables other than the one under consideration. When creating theories, the objective is to find ones which are at least as simple in information requirements, more precise in predictions, and more fruitful in generating additional research than prior theories. While neoclassical economic theory constitutes both the dominant or orthodox theoretical as well as methodological framework, economic theory can also take the form of other schools of thought such as in heterodox economic theories. In
microeconomics Microeconomics is a branch of mainstream economics that studies the behavior of individuals and firms in making decisions regarding the allocation of scarce resources and the interactions among these individuals and firms. Microeconomics fo ...
, principal concepts include
supply and demand In microeconomics, supply and demand is an economic model of price determination in a Market (economics), market. It postulates that, Ceteris paribus, holding all else equal, in a perfect competition, competitive market, the unit price for a ...
,
marginalism Marginalism is a theory of economics that attempts to explain the discrepancy in the value of goods and services by reference to their secondary, or marginal, utility. It states that the reason why the price of diamonds is higher than that of wa ...
,
rational choice theory Rational choice theory refers to a set of guidelines that help understand economic and social behaviour. The theory originated in the eighteenth century and can be traced back to political economist and philosopher, Adam Smith. The theory postula ...
,
opportunity cost In microeconomic theory, the opportunity cost of a particular activity is the value or benefit given up by engaging in that activity, relative to engaging in an alternative activity. More effective it means if you chose one activity (for example ...
,
budget constraint In economics, a budget constraint represents all the combinations of goods and services that a consumer may purchase given current prices within his or her given income. Consumer theory uses the concepts of a budget constraint and a preference ...
s, utility, and the theory of the firm. Early macroeconomic models focused on modelling the relationships between aggregate variables, but as the relationships appeared to change over time macroeconomists, including new Keynesians, reformulated their models in microfoundations. The aforementioned microeconomic concepts play a major part in macroeconomic models – for instance, in monetary theory, the quantity theory of money predicts that increases in the growth rate of the money supply increase inflation, and inflation is assumed to be influenced by rational expectations. In development economics, slower growth in developed nations has been sometimes predicted because of the declining marginal returns of investment and capital, and this has been observed in the Four Asian Tigers. Sometimes an economic hypothesis is only ''
qualitative Qualitative descriptions or distinctions are based on some quality or characteristic rather than on some quantity or measured value. Qualitative may also refer to: *Qualitative property, a property that can be observed but not measured numericall ...
'', not ''quantitative''. Expositions of economic reasoning often use two-dimensional graphs to illustrate theoretical relationships. At a higher level of generality,
mathematical economics Mathematical economics is the application of mathematical methods to represent theories and analyze problems in economics. Often, these applied methods are beyond simple geometry, and may include differential and integral calculus, difference an ...
is the application of mathematical methods to represent theories and analyze problems in economics. Paul Samuelson's treatise '' Foundations of Economic Analysis'' (1947) exemplifies the method, particularly as to maximizing behavioral relations of agents reaching equilibrium. The book focused on examining the class of statements called ''operationally meaningful theorems'' in economics, which are theorems that can conceivably be refuted by empirical data.


Empirical research

Economic theories are frequently tested
empirical Empirical evidence for a proposition is evidence, i.e. what supports or counters this proposition, that is constituted by or accessible to sense experience or experimental procedure. Empirical evidence is of central importance to the sciences and ...
ly, largely through the use of econometrics using economic data. The controlled experiments common to the physical sciences are difficult and uncommon in economics, and instead broad data is observationally studied; this type of testing is typically regarded as less rigorous than controlled experimentation, and the conclusions typically more tentative. However, the field of experimental economics is growing, and increasing use is being made of natural experiments. Statistical methods such as regression analysis are common. Practitioners use such methods to estimate the size, economic significance, and
statistical significance In statistical hypothesis testing, a result has statistical significance when it is very unlikely to have occurred given the null hypothesis (simply by chance alone). More precisely, a study's defined significance level, denoted by \alpha, is the p ...
("signal strength") of the hypothesized relation(s) and to adjust for noise from other variables. By such means, a hypothesis may gain acceptance, although in a probabilistic, rather than certain, sense. Acceptance is dependent upon the falsifiable hypothesis surviving tests. Use of commonly accepted methods need not produce a final conclusion or even a consensus on a particular question, given different tests, data sets, and prior beliefs. Criticisms based on professional standards and non- replicability of results serve as further checks against bias, errors, and overgeneralization, although much economic research has been accused of being non-replicable, and prestigious journals have been accused of not facilitating replication through the provision of the code and data. Like theories, uses of test statistics are themselves open to critical analysis, although critical commentary on papers in economics in prestigious journals such as the ''
American Economic Review The ''American Economic Review'' is a monthly peer-reviewed academic journal published by the American Economic Association. First published in 1911, it is considered one of the most prestigious and highly distinguished journals in the field of ec ...
'' has declined precipitously in the past 40 years. This has been attributed to journals' incentives to maximize citations in order to rank higher on the Social Science Citation Index (SSCI). In applied economics, input–output models employing
linear programming Linear programming (LP), also called linear optimization, is a method to achieve the best outcome (such as maximum profit or lowest cost) in a mathematical model whose requirements are represented by linear function#As a polynomial function, li ...
methods are quite common. Large amounts of data are run through computer programs to analyse the impact of certain policies; IMPLAN is one well-known example. Experimental economics has promoted the use of scientifically controlled experiments. This has reduced the long-noted distinction of economics from
natural science Natural science is one of the branches of science concerned with the description, understanding and prediction of natural phenomena, based on empirical evidence from observation and experimentation. Mechanisms such as peer review and repeatab ...
s because it allows direct tests of what were previously taken as axioms. In some cases these have found that the axioms are not entirely correct; for example, the ultimatum game has revealed that people reject unequal offers. In behavioural economics, psychologist
Daniel Kahneman Daniel Kahneman (; he, דניאל כהנמן; born March 5, 1934) is an Israeli-American psychologist and economist notable for his work on the psychology of judgment and decision-making, as well as behavioral economics, for which he was award ...
won the Nobel Prize in economics in 2002 for his and
Amos Tversky Amos Nathan Tversky ( he, עמוס טברסקי; March 16, 1937 – June 2, 1996) was an Israeli cognitive and mathematical psychologist and a key figure in the discovery of systematic human cognitive bias and handling of risk. Much of his ...
's empirical discovery of several
cognitive bias A cognitive bias is a systematic pattern of deviation from norm or rationality in judgment. Individuals create their own "subjective reality" from their perception of the input. An individual's construction of reality, not the objective input, m ...
es and heuristics. Similar empirical testing occurs in neuroeconomics. Another example is the assumption of narrowly selfish preferences versus a model that tests for selfish, altruistic, and cooperative preferences. These techniques have led some to argue that economics is a "genuine science".


Branches of economics


Microeconomics

Microeconomics examines how entities, forming a market structure, interact within a market to create a market system. These entities include private and public players with various classifications, typically operating under scarcity of tradable units and light government regulation. The item traded may be a tangible product such as apples or a
service Service may refer to: Activities * Administrative service, a required part of the workload of university faculty * Civil service, the body of employees of a government * Community service, volunteer service for the benefit of a community or a pu ...
such as repair services, legal counsel, or entertainment. In theory, in a free market the aggregates (sum of) of ''quantity demanded'' by buyers and ''quantity supplied'' by sellers may reach economic equilibrium over time in reaction to price changes; in practice, various issues may prevent equilibrium, and any equilibrium reached may not necessarily be morally equitable. For example, if the supply of healthcare services is limited by external factors, the equilibrium price may be unaffordable for many who desire it but cannot pay for it. Various market structures exist. In perfectly competitive markets, no participants are large enough to have the market power to set the price of a homogeneous product. In other words, every participant is a "price taker" as no participant influences the price of a product. In the real world, markets often experience imperfect competition. Forms include monopoly (in which there is only one seller of a good),
duopoly A duopoly (from Greek δύο, ''duo'' "two" and πωλεῖν, ''polein'' "to sell") is a type of oligopoly where two firms have dominant or exclusive control over a market. It is the most commonly studied form of oligopoly due to its simplicit ...
(in which there are only two sellers of a good), oligopoly (in which there are few sellers of a good), monopolistic competition (in which there are many sellers producing highly differentiated goods), monopsony (in which there is only one buyer of a good), and oligopsony (in which there are few buyers of a good). Unlike perfect competition, imperfect competition invariably means market power is unequally distributed. Firms under imperfect competition have the potential to be "price makers", which means that, by holding a disproportionately high share of market power, they can influence the prices of their products. Microeconomics studies individual markets by simplifying the economic system by assuming that activity in the market being analysed does not affect other markets. This method of analysis is known as partial-equilibrium analysis (supply and demand). This method aggregates (the sum of all activity) in only one market. General-equilibrium theory studies various markets and their behaviour. It aggregates (the sum of all activity) across ''all'' markets. This method studies both changes in markets and their interactions leading towards equilibrium.


Production, cost, and efficiency

In microeconomics, production is the conversion of inputs into outputs. It is an economic process that uses inputs to create a
commodity In economics, a commodity is an economic good, usually a resource, that has full or substantial fungibility: that is, the market treats instances of the good as equivalent or nearly so with no regard to who produced them. The price of a comm ...
or a service for exchange or direct use. Production is a
flow Flow may refer to: Science and technology * Fluid flow, the motion of a gas or liquid * Flow (geomorphology), a type of mass wasting or slope movement in geomorphology * Flow (mathematics), a group action of the real numbers on a set * Flow (psych ...
and thus a rate of output per period of time. Distinctions include such production alternatives as for consumption (food, haircuts, etc.) vs.
investment goods The economic concept of a capital good (also called complex product systems (CoPS),H. Rush, "Managing innovation in complex product systems (CoPS)," IEE Colloquium on EPSRC Technology Management Initiative (Engineering & Physical Sciences Researc ...
(new tractors, buildings, roads, etc.),
public good Public good may refer to: * Public good (economics), an economic good that is both non-excludable and non-rivalrous * The common good, outcomes that are beneficial for all or most members of a community See also * Digital public goods Digital pu ...
s (national defence, smallpox vaccinations, etc.) or private goods (new computers, bananas, etc.), and "guns" vs "butter".
Opportunity cost In microeconomic theory, the opportunity cost of a particular activity is the value or benefit given up by engaging in that activity, relative to engaging in an alternative activity. More effective it means if you chose one activity (for example ...
is the economic cost of production: the value of the next best opportunity foregone. Choices must be made between desirable yet mutually exclusive actions. It has been described as expressing "the basic relationship between scarcity and choice". For example, if a baker uses a sack of flour to make pretzels one morning, then the baker cannot use either the flour or the morning to make bagels instead. Part of the cost of making pretzels is that neither the flour nor the morning are available any longer, for use in some other way. The opportunity cost of an activity is an element in ensuring that scarce resources are used efficiently, such that the cost is weighed against the value of that activity in deciding on more or less of it. Opportunity costs are not restricted to monetary or financial costs but could be measured by the real cost of output forgone, leisure, or anything else that provides the alternative benefit ( utility). Inputs used in the production process include such primary factors of production as labour services,
capital Capital may refer to: Common uses * Capital city, a municipality of primary status ** List of national capital cities * Capital letter, an upper-case letter Economics and social sciences * Capital (economics), the durable produced goods used f ...
(durable produced goods used in production, such as an existing factory), and land (including natural resources). Other inputs may include intermediate goods used in production of final goods, such as the steel in a new car.
Economic efficiency In microeconomics, economic efficiency, depending on the context, is usually one of the following two related concepts: * Allocative or Pareto efficiency: any changes made to assist one person would harm another. * Productive efficiency: no addit ...
measures how well a system generates desired output with a given set of inputs and available technology. Efficiency is improved if more output is generated without changing inputs, or in other words, the amount of "waste" is reduced. A widely accepted general standard is Pareto efficiency, which is reached when no further change can make someone better off without making someone else worse off. The
production–possibility frontier A production–possibility frontier (PPF), production possibility curve (PPC), or production possibility boundary (PPB), or transformation curve/boundary/frontier is a curve which shows various combinations of the amounts of two goods which can be ...
(PPF) is an expository figure for representing scarcity, cost, and efficiency. In the simplest case an economy can produce just two goods (say "guns" and "butter"). The PPF is a table or graph (as at the right) showing the different quantity combinations of the two goods producible with a given technology and total factor inputs, which limit feasible total output. Each point on the curve shows potential total output for the economy, which is the maximum feasible output of one good, given a feasible output quantity of the other good. Scarcity is represented in the figure by people being willing but unable in the aggregate to consume ''beyond the PPF'' (such as at ''X'') and by the negative slope of the curve. If production of one good ''increases'' along the curve, production of the other good ''decreases'', an inverse relationship. This is because increasing output of one good requires transferring inputs to it from production of the other good, decreasing the latter. The slope of the curve at a point on it gives the trade-off between the two goods. It measures what an additional unit of one good costs in units forgone of the other good, an example of a ''real opportunity cost''. Thus, if one more Gun costs 100 units of butter, the opportunity cost of one Gun is 100 Butter. ''Along the PPF'', scarcity implies that choosing ''more'' of one good in the aggregate entails doing with ''less'' of the other good. Still, in a
market economy A market economy is an economic system in which the decisions regarding investment, production and distribution to the consumers are guided by the price signals created by the forces of supply and demand, where all suppliers and consumers ...
, movement along the curve may indicate that the choice of the increased output is anticipated to be worth the cost to the agents. By construction, each point on the curve shows '' productive efficiency'' in maximizing output for given total inputs. A point ''inside'' the curve (as at ''A''), is feasible but represents ''production inefficiency'' (wasteful use of inputs), in that output of ''one or both goods'' could increase by moving in a northeast direction to a point on the curve. Examples cited of such inefficiency include high unemployment during a business-cycle recession or economic organization of a country that discourages full use of resources. Being on the curve might still not fully satisfy allocative efficiency (also called Pareto efficiency) if it does not produce a mix of goods that consumers prefer over other points. Much applied economics in public policy is concerned with determining how the efficiency of an economy can be improved. Recognizing the reality of scarcity and then figuring out how to organize society for the most efficient use of resources has been described as the "essence of economics", where the subject "makes its unique contribution."


Specialization

Specialization is considered key to economic efficiency based on theoretical and
empirical Empirical evidence for a proposition is evidence, i.e. what supports or counters this proposition, that is constituted by or accessible to sense experience or experimental procedure. Empirical evidence is of central importance to the sciences and ...
considerations. Different individuals or nations may have different real opportunity costs of production, say from differences in
stocks Stocks are feet restraining devices that were used as a form of corporal punishment and public humiliation. The use of stocks is seen as early as Ancient Greece, where they are described as being in use in Solon's law code. The law describing ...
of
human capital Human capital is a concept used by social scientists to designate personal attributes considered useful in the production process. It encompasses employee knowledge, skills, know-how, good health, and education. Human capital has a substantial ...
per worker or
capital Capital may refer to: Common uses * Capital city, a municipality of primary status ** List of national capital cities * Capital letter, an upper-case letter Economics and social sciences * Capital (economics), the durable produced goods used f ...
/ labour ratios. According to theory, this may give a comparative advantage in production of goods that make more intensive use of the relatively more abundant, thus ''relatively'' cheaper, input. Even if one region has an
absolute advantage In economics, the principle of absolute advantage is the ability of a party (an individual, or firm, or country) to produce a good or service more efficiently than its competitors. The Scottish economist Adam Smith first described the principle o ...
as to the ratio of its outputs to inputs in every type of output, it may still specialize in the output in which it has a comparative advantage and thereby gain from trading with a region that lacks any absolute advantage but has a comparative advantage in producing something else. It has been observed that a high volume of trade occurs among regions even with access to a similar technology and mix of factor inputs, including high-income countries. This has led to investigation of economies of
scale Scale or scales may refer to: Mathematics * Scale (descriptive set theory), an object defined on a set of points * Scale (ratio), the ratio of a linear dimension of a model to the corresponding dimension of the original * Scale factor, a number ...
and agglomeration to explain specialization in similar but differentiated product lines, to the overall benefit of respective trading parties or regions. The general theory of specialization applies to trade among individuals, farms, manufacturers,
service Service may refer to: Activities * Administrative service, a required part of the workload of university faculty * Civil service, the body of employees of a government * Community service, volunteer service for the benefit of a community or a pu ...
providers, and economies. Among each of these production systems, there may be a corresponding ''
division of labour The division of labour is the separation of the tasks in any economic system or organisation so that participants may specialise (specialisation). Individuals, organizations, and nations are endowed with, or acquire specialised capabilities, and ...
'' with different work groups specializing, or correspondingly different types of capital equipment and differentiated land uses. An example that combines features above is a country that specializes in the production of high-tech knowledge products, as developed countries do, and trades with developing nations for goods produced in factories where labour is relatively cheap and plentiful, resulting in different in opportunity costs of production. More total output and utility thereby results from specializing in production and trading than if each country produced its own high-tech and low-tech products. Theory and observation set out the conditions such that market prices of outputs and productive inputs select an allocation of factor inputs by comparative advantage, so that (relatively) low-cost inputs go to producing low-cost outputs. In the process, aggregate output may increase as a
by-product A by-product or byproduct is a secondary product derived from a production process, manufacturing process or chemical reaction; it is not the primary product or service being produced. A by-product can be useful and marketable or it can be consid ...
or by design. Such specialization of production creates opportunities for
gains from trade In economics, gains from trade are the net benefits to economic agents from being allowed an increase in voluntary trading with each other. In technical terms, they are the increase of consumer surplus plus producer surplus from lower tariffs ...
whereby resource owners benefit from trade in the sale of one type of output for other, more highly valued goods. A measure of gains from trade is the ''increased income levels'' that trade may facilitate.


Supply and demand

Prices and quantities In economics, nominal value is measured in terms of money, whereas real value is measured against goods or services. A real value is one which has been adjusted for inflation, enabling comparison of quantities as if the prices of goods had not c ...
have been described as the most directly observable attributes of goods produced and exchanged in a
market economy A market economy is an economic system in which the decisions regarding investment, production and distribution to the consumers are guided by the price signals created by the forces of supply and demand, where all suppliers and consumers ...
. The theory of supply and demand is an organizing principle for explaining how prices coordinate the amounts produced and consumed. In
microeconomics Microeconomics is a branch of mainstream economics that studies the behavior of individuals and firms in making decisions regarding the allocation of scarce resources and the interactions among these individuals and firms. Microeconomics fo ...
, it applies to price and output determination for a market with
perfect competition In economics, specifically general equilibrium theory, a perfect market, also known as an atomistic market, is defined by several idealizing conditions, collectively called perfect competition, or atomistic competition. In Economic model, theoret ...
, which includes the condition of no buyers or sellers large enough to have price-setting power. For a given market of a
commodity In economics, a commodity is an economic good, usually a resource, that has full or substantial fungibility: that is, the market treats instances of the good as equivalent or nearly so with no regard to who produced them. The price of a comm ...
, ''demand'' is the relation of the quantity that all buyers would be prepared to purchase at each unit price of the good. Demand is often represented by a table or a graph showing price and quantity demanded (as in the figure). Demand theory describes individual consumers as rationally choosing the most preferred quantity of each good, given income, prices, tastes, etc. A term for this is "constrained utility maximization" (with income and wealth as the constraints on demand). Here, utility refers to the hypothesized relation of each individual consumer for ranking different commodity bundles as more or less preferred. The law of demand states that, in general, price and quantity demanded in a given market are inversely related. That is, the higher the price of a product, the less of it people would be prepared to buy (other things unchanged). As the price of a commodity falls, consumers move toward it from relatively more expensive goods (the substitution effect). In addition, purchasing power from the price decline increases ability to buy (the
income effect The theory of consumer choice is the branch of microeconomics that relates preferences to consumption expenditures and to consumer demand curves. It analyzes how consumers maximize the desirability of their consumption as measured by their pre ...
). Other factors can change demand; for example an increase in income will shift the demand curve for a normal good outward relative to the origin, as in the figure. All determinants are predominantly taken as constant factors of demand and supply. ''Supply'' is the relation between the price of a good and the quantity available for sale at that price. It may be represented as a table or graph relating price and quantity supplied. Producers, for example business firms, are hypothesized to be ''profit maximizers'', meaning that they attempt to produce and supply the amount of goods that will bring them the highest profit. Supply is typically represented as a function relating price and quantity, if other factors are unchanged. That is, the higher the price at which the good can be sold, the more of it producers will supply, as in the figure. The higher price makes it profitable to increase production. Just as on the demand side, the position of the supply can shift, say from a change in the price of a productive input or a technical improvement. The "Law of Supply" states that, in general, a rise in price leads to an expansion in supply and a fall in price leads to a contraction in supply. Here as well, the determinants of supply, such as price of substitutes, cost of production, technology applied and various factors inputs of production are all taken to be constant for a specific time period of evaluation of supply. Market equilibrium occurs where quantity supplied equals quantity demanded, the intersection of the supply and demand curves in the figure above. At a price below equilibrium, there is a shortage of quantity supplied compared to quantity demanded. This is posited to bid the price up. At a price above equilibrium, there is a surplus of quantity supplied compared to quantity demanded. This pushes the price down. The model of supply and demand predicts that for given supply and demand curves, price and quantity will stabilize at the price that makes quantity supplied equal to quantity demanded. Similarly, demand-and-supply theory predicts a new price-quantity combination from a shift in demand (as to the figure), or in supply.


Firms

People frequently do not trade directly on markets. Instead, on the supply side, they may work in and produce through ''firms''. The most obvious kinds of firms are corporations, partnerships and trusts. According to Ronald Coase, people begin to organize their production in firms when the costs of doing business becomes lower than doing it on the market. Firms combine labour and capital, and can achieve far greater economies of scale (when the average cost per unit declines as more units are produced) than individual market trading. In
perfectly competitive In economics, specifically general equilibrium theory, a perfect market, also known as an atomistic market, is defined by several idealizing conditions, collectively called perfect competition, or atomistic competition. In theoretical models wh ...
markets studied in the theory of supply and demand, there are many producers, none of which significantly influence price. Industrial organization generalizes from that special case to study the strategic behaviour of firms that do have significant control of price. It considers the structure of such markets and their interactions. Common market structures studied besides perfect competition include monopolistic competition, various forms of oligopoly, and monopoly. Managerial economics applies
microeconomic Microeconomics is a branch of mainstream economics that studies the behavior of individuals and firms in making decisions regarding the allocation of scarce resources and the interactions among these individuals and firms. Microeconomics fo ...
analysis to specific decisions in business firms or other management units. It draws heavily from quantitative methods such as operations research and programming and from statistical methods such as regression analysis in the absence of certainty and perfect knowledge. A unifying theme is the attempt to optimize business decisions, including unit-cost minimization and profit maximization, given the firm's objectives and constraints imposed by technology and market conditions.


Uncertainty and game theory

Uncertainty in economics is an unknown prospect of gain or loss, whether quantifiable as risk or not. Without it, household behaviour would be unaffected by uncertain employment and income prospects,
financial Finance is the study and discipline of money, currency and capital assets. It is related to, but not synonymous with economics, the study of production, distribution, and consumption of money, assets, goods and services (the discipline of fina ...
and
capital market A capital market is a financial market in which long-term debt (over a year) or equity-backed securities are bought and sold, in contrast to a money market where short-term debt is bought and sold. Capital markets channel the wealth of savers t ...
s would reduce to exchange of a single instrument in each market period, and there would be no communications industry. Given its different forms, there are various ways of representing uncertainty and modelling economic agents' responses to it.
Game theory Game theory is the study of mathematical models of strategic interactions among rational agents. Myerson, Roger B. (1991). ''Game Theory: Analysis of Conflict,'' Harvard University Press, p.&nbs1 Chapter-preview links, ppvii–xi It has appli ...
is a branch of applied mathematics that considers strategic interactions between agents, one kind of uncertainty. It provides a mathematical foundation of industrial organization, discussed above, to model different types of firm behaviour, for example in a solipsistic industry (few sellers), but equally applicable to wage negotiations,
bargaining In the social sciences, bargaining or haggling is a type of negotiation in which the buyer and seller of a good or service debate the price or nature of a transaction. If the bargaining produces agreement on terms, the transaction takes plac ...
, contract design, and any situation where individual agents are few enough to have perceptible effects on each other. In behavioural economics, it has been used to model the strategies agents choose when interacting with others whose interests are at least partially adverse to their own. In this, it generalizes maximization approaches developed to analyse market actors such as in the
supply and demand In microeconomics, supply and demand is an economic model of price determination in a Market (economics), market. It postulates that, Ceteris paribus, holding all else equal, in a perfect competition, competitive market, the unit price for a ...
model and allows for incomplete information of actors. The field dates from the 1944 classic ''
Theory of Games and Economic Behavior ''Theory of Games and Economic Behavior'', published in 1944 by Princeton University Press, is a book by mathematician John von Neumann and economist Oskar Morgenstern which is considered the groundbreaking text that created the interdisciplinar ...
'' by John von Neumann and Oskar Morgenstern. It has significant applications seemingly outside of economics in such diverse subjects as the formulation of nuclear strategies, ethics, political science, and evolutionary biology. Risk aversion may stimulate activity that in well-functioning markets smooths out risk and communicates information about risk, as in markets for insurance, commodity futures contracts, and financial instruments. Financial economics or simply
finance Finance is the study and discipline of money, currency and capital assets. It is related to, but not synonymous with economics, the study of production, distribution, and consumption of money, assets, goods and services (the discipline of fina ...
describes the allocation of financial resources. It also analyses the pricing of financial instruments, the financial structure of companies, the efficiency and fragility of financial markets, financial crises, and related government policy or regulation. Some market organizations may give rise to inefficiencies associated with uncertainty. Based on George Akerlof's " Market for Lemons" article, the
paradigm In science and philosophy, a paradigm () is a distinct set of concepts or thought patterns, including theories, research methods, postulates, and standards for what constitute legitimate contributions to a field. Etymology ''Paradigm'' comes f ...
example is of a dodgy second-hand car market. Customers without knowledge of whether a car is a "lemon" depress its price below what a quality second-hand car would be. Information asymmetry arises here, if the seller has more relevant information than the buyer but no incentive to disclose it. Related problems in insurance are adverse selection, such that those at most risk are most likely to insure (say reckless drivers), and moral hazard, such that insurance results in riskier behaviour (say more reckless driving). Both problems may raise insurance costs and reduce efficiency by driving otherwise willing transactors from the market (" incomplete markets"). Moreover, attempting to reduce one problem, say adverse selection by mandating insurance, may add to another, say moral hazard. Information economics, which studies such problems, has relevance in subjects such as insurance, contract law, mechanism design, monetary economics, and
health care Health care or healthcare is the improvement of health via the prevention, diagnosis, treatment, amelioration or cure of disease, illness, injury, and other physical and mental impairments in people. Health care is delivered by health profe ...
. Applied subjects include market and legal remedies to spread or reduce risk, such as warranties, government-mandated partial insurance, restructuring or bankruptcy law, inspection, and regulation for quality and information disclosure.


Market failure

The term " market failure" encompasses several problems which may undermine standard economic assumptions. Although economists categorize market failures differently, the following categories emerge in the main texts. Authors critical of economics tend to view the talk of "market failiures", as a term which is used when economic theories don't correspond with reality, making these theories and paradigms in which these terms are used unfalsifiable.
Information asymmetries In contract theory and economics, information asymmetry deals with the study of decisions in transactions where one party has more or better information than the other. Information asymmetry creates an imbalance of power in transactions, which c ...
and incomplete markets may result in economic inefficiency but also a possibility of improving efficiency through market, legal, and regulatory remedies, as discussed above. Natural monopoly, or the overlapping concepts of "practical" and "technical" monopoly, is an extreme case of ''failure of competition'' as a restraint on producers. Extreme economies of scale are one possible cause. Public goods are goods which are under-supplied in a typical market. The defining features are that people can consume public goods without having to pay for them and that more than one person can consume the good at the same time. Externalities occur where there are significant social costs or benefits from production or consumption that are not reflected in market prices. For example, air pollution may generate a negative externality, and education may generate a positive externality (less crime, etc.). Governments often tax and otherwise restrict the sale of goods that have negative externalities and subsidize or otherwise promote the purchase of goods that have positive externalities in an effort to correct the price distortions caused by these externalities. Elementary demand-and-supply theory predicts equilibrium but not the speed of adjustment for changes of equilibrium due to a shift in demand or supply. In many areas, some form of
price stickiness Nominal rigidity, also known as price-stickiness or wage-stickiness, is a situation in which a nominal price is resistant to change. Complete nominal rigidity occurs when a price is fixed in nominal terms for a relevant period of time. For exampl ...
is postulated to account for quantities, rather than prices, adjusting in the short run to changes on the demand side or the supply side. This includes standard analysis of the business cycle in
macroeconomics Macroeconomics (from the Greek prefix ''makro-'' meaning "large" + ''economics'') is a branch of economics dealing with performance, structure, behavior, and decision-making of an economy as a whole. For example, using interest rates, taxes, and ...
. Analysis often revolves around causes of such price stickiness and their implications for reaching a hypothesized long-run equilibrium. Examples of such price stickiness in particular markets include wage rates in labour markets and posted prices in markets deviating from
perfect competition In economics, specifically general equilibrium theory, a perfect market, also known as an atomistic market, is defined by several idealizing conditions, collectively called perfect competition, or atomistic competition. In Economic model, theoret ...
. Some specialized fields of economics deal in market failure more than others. The
economics of the public sector Public economics ''(or economics of the public sector)'' is the study of government policy through the lens of economic efficiency and equity. Public economics builds on the theory of welfare economics and is ultimately used as a tool to improve ...
is one example. Much environmental economics concerns externalities or " public bads". Policy options include regulations that reflect cost-benefit analysis or market solutions that change incentives, such as emission fees or redefinition of property rights.


Welfare

Welfare economics uses microeconomics techniques to evaluate well-being from allocation of productive factors as to desirability and
economic efficiency In microeconomics, economic efficiency, depending on the context, is usually one of the following two related concepts: * Allocative or Pareto efficiency: any changes made to assist one person would harm another. * Productive efficiency: no addit ...
within an economy, often relative to competitive general equilibrium. It analyzes ''social welfare'', however
measured Measurement is the quantification of attributes of an object or event, which can be used to compare with other objects or events. In other words, measurement is a process of determining how large or small a physical quantity is as compared t ...
, in terms of economic activities of the individuals that compose the theoretical society considered. Accordingly, individuals, with associated economic activities, are the basic units for aggregating to social welfare, whether of a group, a community, or a society, and there is no "social welfare" apart from the "welfare" associated with its individual units.


Macroeconomics

Macroeconomics examines the economy as a whole to explain broad aggregates and their interactions "top down", that is, using a simplified form of general-equilibrium theory. Such aggregates include national income and output, the unemployment rate, and price inflation and subaggregates like total consumption and investment spending and their components. It also studies effects of monetary policy and fiscal policy. Since at least the 1960s, macroeconomics has been characterized by further integration as to micro-based modelling of sectors, including
rationality Rationality is the quality of being guided by or based on reasons. In this regard, a person acts rationally if they have a good reason for what they do or a belief is rational if it is based on strong evidence. This quality can apply to an abil ...
of players, efficient use of market information, and imperfect competition. This has addressed a long-standing concern about inconsistent developments of the same subject. Macroeconomic analysis also considers factors affecting the long-term level and growth of national income. Such factors include capital accumulation, technological change and labour force growth.


Growth

''Growth economics'' studies factors that explain
economic growth Economic growth can be defined as the increase or improvement in the inflation-adjusted market value of the goods and services produced by an economy in a financial year. Statisticians conventionally measure such growth as the percent rate of ...
 – the increase in output '' per capita'' of a country over a long period of time. The same factors are used to explain differences in the ''level'' of output ''per capita'' ''between'' countries, in particular why some countries grow faster than others, and whether countries converge at the same rates of growth. Much-studied factors include the rate of
investment Investment is the dedication of money to purchase of an asset to attain an increase in value over a period of time. Investment requires a sacrifice of some present asset, such as time, money, or effort. In finance, the purpose of investing i ...
,
population growth Population growth is the increase in the number of people in a population or dispersed group. Actual global human population growth amounts to around 83 million annually, or 1.1% per year. The global population has grown from 1 billion in 1800 to ...
, and technological change. These are represented in theoretical and
empirical Empirical evidence for a proposition is evidence, i.e. what supports or counters this proposition, that is constituted by or accessible to sense experience or experimental procedure. Empirical evidence is of central importance to the sciences and ...
forms (as in the neoclassical and
endogenous Endogenous substances and processes are those that originate from within a living system such as an organism, tissue, or cell. In contrast, exogenous substances and processes are those that originate from outside of an organism. For example, es ...
growth models) and in growth accounting.


Business cycle

The economics of a depression were the spur for the creation of "macroeconomics" as a separate discipline. During the
Great Depression The Great Depression (19291939) was an economic shock that impacted most countries across the world. It was a period of economic depression that became evident after a major fall in stock prices in the United States. The economic contagio ...
of the 1930s, John Maynard Keynes authored a book entitled '' The General Theory of Employment, Interest and Money'' outlining the key theories of Keynesian economics. Keynes contended that
aggregate demand In macroeconomics, aggregate demand (AD) or domestic final demand (DFD) is the total demand for final goods and services in an economy at a given time. It is often called effective demand, though at other times this term is distinguished. This is ...
for goods might be insufficient during economic downturns, leading to unnecessarily high unemployment and losses of potential output. He therefore advocated active policy responses by the public sector, including monetary policy actions by the central bank and fiscal policy actions by the government to stabilize output over the business cycle. Thus, a central conclusion of Keynesian economics is that, in some situations, no strong automatic mechanism moves output and employment towards
full employment Full employment is a situation in which there is no cyclical or unemployment#Cyclical unemployment, deficient-demand unemployment. Full employment does not entail the disappearance of all unemployment, as other kinds of unemployment, namely Structu ...
levels. John Hicks' IS/LM model has been the most influential interpretation of ''The General Theory''. Over the years, understanding of the business cycle has branched into various research programmes, mostly related to or distinct from Keynesianism. The
neoclassical synthesis The neoclassical synthesis (NCS), neoclassical–Keynesian synthesis, or just neo-Keynesianism was a neoclassical economics academic movement and paradigm in economics that worked towards reconciling the macroeconomic thought of John Maynard Key ...
refers to the reconciliation of Keynesian economics with neoclassical economics, stating that Keynesianism is correct in the short run but qualified by neoclassical-like considerations in the intermediate and long run. New classical macroeconomics, as distinct from the Keynesian view of the business cycle, posits market clearing with imperfect information. It includes Friedman's permanent income hypothesis on consumption and " rational expectations" theory, led by Robert Lucas, and real business cycle theory. In contrast, the new Keynesian approach retains the rational expectations assumption, however it assumes a variety of
market failures In neoclassical economics, market failure is a situation in which the allocation of goods and services by a free market is not Pareto efficient, often leading to a net loss of economic value. Market failures can be viewed as scenarios where ...
. In particular, New Keynesians assume prices and wages are " sticky", which means they do not adjust instantaneously to changes in economic conditions. Thus, the new classicals assume that prices and wages adjust automatically to attain full employment, whereas the new Keynesians see full employment as being automatically achieved only in the long run, and hence government and central-bank policies are needed because the "long run" may be very long.


Unemployment

The amount of unemployment in an economy is measured by the unemployment rate, the percentage of workers without jobs in the labour force. The labour force only includes workers actively looking for jobs. People who are retired, pursuing education, or discouraged from seeking work by a lack of job prospects are excluded from the labour force. Unemployment can be generally broken down into several types that are related to different causes. Classical models of unemployment occurs when wages are too high for employers to be willing to hire more workers. Consistent with classical unemployment, frictional unemployment occurs when appropriate job vacancies exist for a worker, but the length of time needed to search for and find the job leads to a period of unemployment.
Structural unemployment Structural unemployment is a form of involuntary unemployment caused by a mismatch between the skills that workers in the economy can offer, and the skills demanded of workers by employers (also known as the skills gap). Structural unemployment i ...
covers a variety of possible causes of unemployment including a mismatch between workers' skills and the skills required for open jobs. Large amounts of structural unemployment can occur when an economy is transitioning industries and workers find their previous set of skills are no longer in demand. Structural unemployment is similar to frictional unemployment since both reflect the problem of matching workers with job vacancies, but structural unemployment covers the time needed to acquire new skills not just the short term search process. While some types of unemployment may occur regardless of the condition of the economy, cyclical unemployment occurs when growth stagnates. Okun's law represents the empirical relationship between unemployment and economic growth. The original version of Okun's law states that a 3% increase in output would lead to a 1% decrease in unemployment.


Inflation and monetary policy

Money is a ''means of final payment'' for goods in most price system economies, and is the unit of account in which prices are typically stated. Money has general acceptability, relative consistency in value, divisibility, durability, portability, elasticity in supply, and longevity with mass public confidence. It includes currency held by the nonbank public and checkable deposits. It has been described as a
social convention A convention is a set of agreed, stipulated, or generally accepted standards, norms, social norms, or criteria, often taking the form of a custom. In a social context, a convention may retain the character of an "unwritten law" of custom (for ex ...
, like language, useful to one largely because it is useful to others. In the words of Francis Amasa Walker, a well-known 19th-century economist, "Money is what money does" ("Money is ''that'' money does" in the original). As a medium of exchange, money facilitates trade. It is essentially a measure of value and more importantly, a store of value being a basis for credit creation. Its economic function can be contrasted with barter (non-monetary exchange). Given a diverse array of produced goods and specialized producers, barter may entail a hard-to-locate double coincidence of wants as to what is exchanged, say apples and a book. Money can reduce the transaction cost of exchange because of its ready acceptability. Then it is less costly for the seller to accept money in exchange, rather than what the buyer produces. At the level of an economy, theory and evidence are consistent with a positive relationship running from the total money supply to the nominal value of total output and to the general price level. For this reason, management of the money supply is a key aspect of monetary policy.


Fiscal policy

Governments implement fiscal policy to influence macroeconomic conditions by adjusting spending and taxation policies to alter aggregate demand. When aggregate demand falls below the potential output of the economy, there is an
output gap The GDP gap or the output gap is the difference between actual GDP or actual output and potential GDP, in an attempt to identify the current economic position over the business cycle. The measure of output gap is largely used in macroeconomic po ...
where some productive capacity is left unemployed. Governments increase spending and cut taxes to boost aggregate demand. Resources that have been idled can be used by the government. For example, unemployed home builders can be hired to expand highways. Tax cuts allow consumers to increase their spending, which boosts aggregate demand. Both tax cuts and spending have multiplier effects where the initial increase in demand from the policy percolates through the economy and generates additional economic activity. The effects of fiscal policy can be limited by crowding out. When there is no output gap, the economy is producing at full capacity and there are no excess productive resources. If the government increases spending in this situation, the government uses resources that otherwise would have been used by the private sector, so there is no increase in overall output. Some economists think that crowding out is always an issue while others do not think it is a major issue when output is depressed. Sceptics of fiscal policy also make the argument of Ricardian equivalence. They argue that an increase in debt will have to be paid for with future tax increases, which will cause people to reduce their consumption and save money to pay for the future tax increase. Under Ricardian equivalence, any boost in demand from tax cuts will be offset by the increased saving intended to pay for future higher taxes.


Public economics

Public economics is the field of economics that deals with economic activities of a public sector, usually government. The subject addresses such matters as tax incidence (who really pays a particular tax), cost-benefit analysis of government programmes, effects on
economic efficiency In microeconomics, economic efficiency, depending on the context, is usually one of the following two related concepts: * Allocative or Pareto efficiency: any changes made to assist one person would harm another. * Productive efficiency: no addit ...
and income distribution of different kinds of spending and taxes, and fiscal politics. The latter, an aspect of
public choice theory Public choice, or public choice theory, is "the use of economic tools to deal with traditional problems of political science".Gordon Tullock, 9872008, "public choice," ''The New Palgrave Dictionary of Economics''. . Its content includes the st ...
, models public-sector behaviour analogously to microeconomics, involving interactions of self-interested voters, politicians, and bureaucrats. Much of economics is positive, seeking to describe and predict economic phenomena. Normative economics seeks to identify what economies ''ought'' to be like. Welfare economics is a normative branch of economics that uses
microeconomic Microeconomics is a branch of mainstream economics that studies the behavior of individuals and firms in making decisions regarding the allocation of scarce resources and the interactions among these individuals and firms. Microeconomics fo ...
techniques to simultaneously determine the allocative efficiency within an economy and the income distribution associated with it. It attempts to measure social welfare by examining the economic activities of the individuals that comprise society.


International economics

International trade studies determinants of goods-and-services flows across international boundaries. It also concerns the size and distribution of
gains from trade In economics, gains from trade are the net benefits to economic agents from being allowed an increase in voluntary trading with each other. In technical terms, they are the increase of consumer surplus plus producer surplus from lower tariffs ...
. Policy applications include estimating the effects of changing tariff rates and trade quotas. International finance is a macroeconomic field which examines the flow of capital across international borders, and the effects of these movements on
exchange rate In finance, an exchange rate is the rate at which one currency will be exchanged for another currency. Currencies are most commonly national currencies, but may be sub-national as in the case of Hong Kong or supra-national as in the case of ...
s. Increased trade in goods, services and capital between countries is a major effect of contemporary globalization.


Labor economics

Labor economics seeks to understand the functioning and dynamics of the markets for wage labor. Labor markets function through the interaction of workers and employers. Labor economics looks at the suppliers of labor services (workers), the demands of labor services (employers), and attempts to understand the resulting pattern of wages, employment, and income. In economics, labor is a measure of the work done by human beings. It is conventionally contrasted with such other factors of production as land and
capital Capital may refer to: Common uses * Capital city, a municipality of primary status ** List of national capital cities * Capital letter, an upper-case letter Economics and social sciences * Capital (economics), the durable produced goods used f ...
. There are theories which have developed a concept called
human capital Human capital is a concept used by social scientists to designate personal attributes considered useful in the production process. It encompasses employee knowledge, skills, know-how, good health, and education. Human capital has a substantial ...
(referring to the skills that workers possess, not necessarily their actual work), although there are also counter posing macro-economic system theories that think human capital is a contradiction in terms.


Development economics

Development economics examines economic aspects of the economic development process in relatively
low-income countries A developing country is a sovereign state with a lesser developed industrial base and a lower Human Development Index (HDI) relative to other countries. However, this definition is not universally agreed upon. There is also no clear agreem ...
focusing on structural change,
poverty Poverty is the state of having few material possessions or little income. Poverty can have diverse social, economic, and political causes and effects. When evaluating poverty in ...
, and
economic growth Economic growth can be defined as the increase or improvement in the inflation-adjusted market value of the goods and services produced by an economy in a financial year. Statisticians conventionally measure such growth as the percent rate of ...
. Approaches in development economics frequently incorporate social and political factors.


Criticism

Economics has historically been subject to criticism that it relies on unrealistic, unverifiable, or highly simplified assumptions, in some cases because these assumptions simplify the proofs of desired conclusions. For example, the economist Friedrich Hayek claimed that economics (at least historically) used a
scientistic Scientism is the opinion that science and the scientific method are the best or only way to render truth about the world and reality. While the term was defined originally to mean "methods and attitudes typical of or attributed to natural scientis ...
approach which he claimed was "''decidedly unscientific in the true sense of the word, since it involves a mechanical and uncritical application of habits of thought to fields different from those in which they have been formed''". Latter-day examples of such assumptions include
perfect information In economics, perfect information (sometimes referred to as "no hidden information") is a feature of perfect competition. With perfect information in a market, all consumers and producers have complete and instantaneous knowledge of all market pr ...
,
profit maximization In economics, profit maximization is the short run or long run process by which a firm may determine the price, input and output levels that will lead to the highest possible total profit (or just profit in short). In neoclassical economics, w ...
and rational choices, axioms of neoclassical economics. Such criticisms often conflate neoclassical economics with all of contemporary economics. The field of information economics includes both mathematical-economical research and also behavioural economics, akin to studies in behavioural psychology, and confounding factors to the neoclassical assumptions are the subject of substantial study in many areas of economics. Prominent historical mainstream economists such as Keynes and Joskow observed that much of the economics of their time was conceptual rather than quantitative, and difficult to model and formalize quantitatively. In a discussion on oligopoly research, Paul Joskow pointed out in 1975 that in practice, serious students of actual economies tended to use "informal models" based upon qualitative factors specific to particular industries. Joskow had a strong feeling that the important work in oligopoly was done through informal observations while formal models were "trotted out '' ex post''". He argued that formal models were largely not important in the empirical work, either, and that the fundamental factor behind the theory of the firm, behaviour, was neglected. Deirdre McCloskey has argued that many empirical economic studies are poorly reported, and she and Stephen Ziliak argue that although her critique has been well-received, practice has not improved. The extent to which practice has improved since the early 2000s is contested: although economists have noted the discipline's adoption of increasingly rigorous modeling, other have criticized the field's focus on creating computer simulations detached from reality, as well as noting the loss of prestige suffered by the field for failing to anticipate the Great Recession. Issues like central bank independence, central bank policies and rhetoric in central bank governors discourse or the premises of macroeconomic policies ( monetary and fiscal policy) of the state are a focus of contention and criticism. In the 1990s, feminist critiques of neoclassical economic models gained prominence, leading to the formation of feminist economics. Feminist economists call attention to the social construction of economics and claims to highlight the ways in which its models and methods reflect masculine preferences. Primary criticisms focus on: the assumed selfish nature of actors ( homo economicus); exogenous tastes ; the difficulty of utility comparisons across agents; the exclusion of unpaid work in Macroeconomic measures; and the lack of consideration for class and gender. Economics has been derogatorily dubbed " the dismal science", first coined by the
Victorian Victorian or Victorians may refer to: 19th century * Victorian era, British history during Queen Victoria's 19th-century reign ** Victorian architecture ** Victorian house ** Victorian decorative arts ** Victorian fashion ** Victorian literature ...
historian Thomas Carlyle in the 19th century. It is often stated that Carlyle gave it this nickname as a response to the work of Thomas Robert Malthus, who predicted widespread starvation resulting from projections that population growth would exceed the rate of increase in the food supply. However, the actual phrase was coined by Carlyle in the context of a debate with John Stuart Mill on slavery, in which Carlyle argued for slavery; the "dismal" nature of economics in Carlyle's view was that it " oundthe secret of this Universe in 'supply and demand', and reduc dthe duty of human governors to that of letting men alone"."


Related subjects

Economics is one social science among several and has fields bordering on other areas, including economic geography, economic history, public choice, energy economics, cultural economics, family economics and
institutional economics Institutional economics focuses on understanding the role of the Sociocultural evolution, evolutionary process and the role of institutions in shaping Economy, economic Human behavior, behavior. Its original focus lay in Thorstein Veblen's instin ...
. Law and economics, or economic analysis of law, is an approach to legal theory that applies methods of economics to law. It includes the use of economic concepts to explain the effects of legal rules, to assess which legal rules are economically efficient, and to predict what the legal rules will be. A seminal article by Ronald Coase published in 1961 suggested that well-defined property rights could overcome the problems of externalities. Political economy is the interdisciplinary study that combines economics, law, and political science in explaining how political institutions, the political environment, and the economic system (capitalist, socialist, mixed) influence each other. It studies questions such as how monopoly, rent-seeking behaviour, and externalities should impact government policy. Historians have employed ''political economy'' to explore the ways in the past that persons and groups with common economic interests have used politics to effect changes beneficial to their interests. Energy economics is a broad scientific subject area which includes topics related to energy supply and energy demand.
Georgescu-Roegen Nicholas Georgescu-Roegen (born Nicolae Georgescu, 4 February 1906 – 30 October 1994) was a Romanian mathematician, statistician and economist. He is best known today for his 1971 ''The Entropy Law and the Economic Process'', in which he argu ...
reintroduced the concept of entropy in relation to economics and energy from thermodynamics, as distinguished from what he viewed as the mechanistic foundation of neoclassical economics drawn from Newtonian physics. His work contributed significantly to thermoeconomics and to ecological economics. He also did foundational work which later developed into evolutionary economics. The sociological subfield of economic sociology arose, primarily through the work of Émile Durkheim,
Max Weber Maximilian Karl Emil Weber (; ; 21 April 186414 June 1920) was a German sociologist, historian, jurist and political economist, who is regarded as among the most important theorists of the development of modern Western society. His ideas profo ...
and
Georg Simmel Georg Simmel (; ; 1 March 1858 – 26 September 1918) was a German sociologist, philosopher, and critic. Simmel was influential in the field of sociology. Simmel was one of the first generation of German sociologists: his neo-Kantian approach l ...
, as an approach to analysing the effects of economic phenomena in relation to the overarching social paradigm (i.e. modernity). Classic works include
Max Weber Maximilian Karl Emil Weber (; ; 21 April 186414 June 1920) was a German sociologist, historian, jurist and political economist, who is regarded as among the most important theorists of the development of modern Western society. His ideas profo ...
's ''The Protestant Ethic and the Spirit of Capitalism'' (1905) and
Georg Simmel Georg Simmel (; ; 1 March 1858 – 26 September 1918) was a German sociologist, philosopher, and critic. Simmel was influential in the field of sociology. Simmel was one of the first generation of German sociologists: his neo-Kantian approach l ...
's ''The Philosophy of Money'' (1900). More recently, the works of James Samuel Coleman, James S. Coleman, Mark Granovetter, Peter Hedstrom and Richard Swedberg have been influential in this field. Gary Becker in 1974 presented an economic theory of social interactions, whose applications included the family economics, family, charity, merit goods and multiperson interactions, and envy and hatred. He and Kevin M. Murphy, Kevin Murphy authored a book in 2001 that analyzed market behavior in a social environment.


Profession

The professionalization of economics, reflected in the growth of graduate programmes on the subject, has been described as "the main change in economics since around 1900". Most major universities and many colleges have a major, school, or department in which academic degrees are awarded in the subject, whether in the liberal arts, business, or for professional study. See Bachelor of Economics and Master of Economics. In the private sector, professional economists are employed as consultants and in industry, including banking and
finance Finance is the study and discipline of money, currency and capital assets. It is related to, but not synonymous with economics, the study of production, distribution, and consumption of money, assets, goods and services (the discipline of fina ...
. Economists also work for various government departments and agencies, for example, the national treasury, central bank or List of national and international statistical services, National Bureau of Statistics. See Economic analyst. There are dozens of prizes awarded to economists each year for outstanding intellectual contributions to the field, the most prominent of which is the Nobel Memorial Prize in Economic Sciences, though it is not a Nobel Prize. Contemporary economics uses mathematics. Economists draw on the tools of calculus, linear algebra, statistics,
game theory Game theory is the study of mathematical models of strategic interactions among rational agents. Myerson, Roger B. (1991). ''Game Theory: Analysis of Conflict,'' Harvard University Press, p.&nbs1 Chapter-preview links, ppvii–xi It has appli ...
, and computer science. Professional economists are expected to be familiar with these tools, while a minority specialize in econometrics and mathematical methods.


Women in economics

Harriet Martineau (1802-1876) was a widely-read populariser of classical economic thought.
Mary Paley Marshall Mary Marshall (née Paley; 24 October 1850 – 19 March 1944) was an economist who in 1874 had been one of the first women to take the Tripos examination at Cambridge University – although, as a woman, she had been excluded from receiving ...
(1850-1944), the first women lecturer at a British economics faculty, wrote ''The Economics of Industry'' with her husband
Alfred Marshall Alfred Marshall (26 July 1842 – 13 July 1924) was an English economist, and was one of the most influential economists of his time. His book '' Principles of Economics'' (1890) was the dominant economic textbook in England for many years. I ...
. Joan Robinson (1903-1983) was an important post-Keynesian economist. The economic historian Anna Schwartz (1915-2012) coauthored ''A Monetary History of the United States, 1867–1960'' with Milton Friedman. Two women have received the Nobel Prize in Economics: Elinor Ostrom (2009) and Esther Duflo (2019). Five have received the John Bates Clark Medal: Susan Athey (2007), Esther Duflo (2010), Amy Finkelstein (2012), Emi Nakamura (2019) and Melissa Dell (2020). Women's authorship share in prominent economic journals reduced from 1940 to the 1970s, but has subsequently risen, with different patterns of gendered coauthorship. Women remain globally under-represented in the profession (19% of authors in the RePEc database in 2018), with national variation.


See also

* Critical juncture theory * Economics terminology that differs from common usage * Economic ideology * Economic policy * Economic union * Free trade * Happiness economics * Humanistic economics * * List of economics films * List of economics awards * Socioeconomics


General

* Glossary of economics * Index of economics articles * JEL classification codes for classifying articles in economics journals and books on economics by subject matter from 1886 to the present. * Outline of economics


Notes


References


Further reading

* * * * *


External links


General information

*
Economic journals on the web.

Economics
at ''Encyclopædia Britannica''
Economics A-Z.
Definitions from ''The Economist''.
Economics Online
(UK-based), with drop-down menus at top, incl. Definitions.
Intute: Economics
Internet directory of UK universities.
Research Papers in Economics (RePEc)

Resources For Economists
: American Economic Association-sponsored guide to 2,000+ Internet resources from "Data" to "Neat Stuff", updated quarterly.


Institutions and organizations


Economics Departments, Institutes and Research Centers in the World

Organization For Co-operation and Economic Development (OECD) Statistics

United Nations Statistics Division

World Bank Data

American Economic Association


Study resources

* *
Economics at About.com
* b:Economics, Economics textbooks on b:Main Page, Wikibooks
MERLOT Learning Materials: Economics
: US-based database of learning materials

UK Economics Network's database of text, slides, glossaries and other resources {{Use dmy dates, date=June 2018 Economics, Economic theories,