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Random Walk Model Of Consumption
The random walk model of consumption was introduced by economist Robert Hall. This model uses the Euler numerical method to model consumption. He created his consumption theory in response to the Lucas critique. Using Euler equations to model the random walk of consumption has become the dominant approach to modeling consumption. Background Hall introduced his famous random walk model of consumption in 1978. His approach is differentiated from earlier theories by the introduction of the Lucas critique to modeling consumption. He incorporated the idea of rational expectations into his consumption models and sets up the model so that consumers will maximize their utility. Theory Robert Hall was the first to derive the effects of rational expectations for consumption. His theory states that if Milton Friedman’s permanent income hypothesis is correct, which in short says current income should be viewed as the sum of permanent income and transitory income and that consumption depends ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Random Walk
In mathematics, a random walk is a random process that describes a path that consists of a succession of random steps on some mathematical space. An elementary example of a random walk is the random walk on the integer number line \mathbb Z which starts at 0, and at each step moves +1 or −1 with equal probability. Other examples include the path traced by a molecule as it travels in a liquid or a gas (see Brownian motion), the search path of a foraging animal, or the price of a fluctuating stock and the financial status of a gambler. Random walks have applications to engineering and many scientific fields including ecology, psychology, computer science, physics, chemistry, biology, economics, and sociology. The term ''random walk'' was first introduced by Karl Pearson in 1905. Lattice random walk A popular random walk model is that of a random walk on a regular lattice, where at each step the location jumps to another site according to some probability distribution. In a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Robert Hall (economist)
Robert Ernest "Bob" Hall (born August 13, 1943) is an American economist and a Robert and Carole McNeil Senior Fellow at Stanford University's Hoover Institution. He is generally considered a macroeconomist, but he describes himself as an "applied economist". Hall received a BA in economics at the University of California, Berkeley, and a PhD in economics from MIT for a thesis titled ''Essays on the Theory of Wealth'' under the supervision of Robert Solow. Hall is a member of the Hoover Institution, the National Academy of Sciences, a fellow at both American Academy of Arts and Sciences and the Econometric Society, and a member of the NBER. He is the chairman of the Business Cycle Dating Committee, the body responsible for setting the start and end dates of U.S. economic recessions. Hall served as president of the American Economic Association in 2010, and is a long-time member of the Brookings Panel on Economic Activity. Ideas Hall has a broad range of interests, includi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Euler Method
In mathematics and computational science, the Euler method (also called forward Euler method) is a first-order numerical procedure for solving ordinary differential equations (ODEs) with a given initial value. It is the most basic explicit method for numerical integration of ordinary differential equations and is the simplest Runge–Kutta method. The Euler method is named after Leonhard Euler, who treated it in his book ''Institutionum calculi integralis'' (published 1768–1870). The Euler method is a first-order method, which means that the local error (error per step) is proportional to the square of the step size, and the global error (error at a given time) is proportional to the step size. The Euler method often serves as the basis to construct more complex methods, e.g., predictor–corrector method. Informal geometrical description Consider the problem of calculating the shape of an unknown curve which starts at a given point and satisfies a given differential equ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Consumption (economics)
Consumption is the act of using resources to satisfy current needs and wants. It is seen in contrast to investing, which is spending for acquisition of ''future'' income. Consumption is a major concept in economics and is also studied in many other social sciences. Different schools of economists define consumption differently. According to mainstream economists, only the final purchase of newly produced goods and services by individuals for immediate use constitutes consumption, while other types of expenditure — in particular, fixed investment, intermediate consumption, and government spending — are placed in separate categories (see consumer choice). Other economists define consumption much more broadly, as the aggregate of all economic activity that does not entail the design, production and marketing of goods and services (e.g. the selection, adoption, use, disposal and recycling of goods and services). Economists are particularly interested in the relationship betwee ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lucas Critique
The Lucas critique, named for American economist Robert Lucas's work on macroeconomic policymaking, argues that it is naive to try to predict the effects of a change in economic policy entirely on the basis of relationships observed in historical data, especially highly aggregated historical data. More formally, it states that the decision rules of Keynesian models—such as the consumption function—cannot be considered as structural in the sense of being invariant with respect to changes in government policy variables. The Lucas critique is significant in the history of economic thought as a representative of the paradigm shift that occurred in macroeconomic theory in the 1970s towards attempts at establishing micro-foundations. Thesis The basic idea pre-dates Lucas's contribution—related ideas are expressed as Campbell's law and Goodhart's law—but in a 1976 paper, Lucas drove to the point that this simple notion invalidated policy advice based on conclusions draw ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rational Expectations
In economics, "rational expectations" are model-consistent expectations, in that agents inside the model A model is an informative representation of an object, person or system. The term originally denoted the plans of a building in late 16th-century English, and derived via French and Italian ultimately from Latin ''modulus'', a measure. Models c ... are assumed to "know the model" and on average take the model's predictions as valid. Rational expectations ensure internal consistency in models involving uncertainty. To obtain consistency within a model, the predictions of future values of economically relevant variables from the model are assumed to be the same as that of the decision-makers in the model, given their information set, the nature of the random processes involved, and model structure. The rational expectations assumption is used especially in many contemporary macroeconomic models. Since most macroeconomic models today study decisions under uncertainty and o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Permanent Income Hypothesis
The permanent income hypothesis (PIH) is a model in the field of economics to explain the formation of consumption patterns. It suggests consumption patterns are formed from future expectations and consumption smoothing. The theory was developed by Milton Friedman and published in his ''A Theory of Consumption Function'', published in 1957 and subsequently formalized by Robert Hall in a rational expectations model. Originally applied to consumption and income, the process of future expectations is thought to influence other phenomena. In its simplest form, the hypothesis states changes in permanent income (human capital, property, assets), rather than changes in temporary income (unexpected income), are what drive changes in consumption. The formation of consumption patterns opposite to predictions was an outstanding problem faced by the Keynesian orthodoxy. Friedman's predictions of consumption smoothing, where people spread out transitory changes in income over time, departe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
United States
The United States of America (U.S.A. or USA), commonly known as the United States (U.S. or US) or America, is a country primarily located in North America. It consists of 50 states, a federal district, five major unincorporated territories, nine Minor Outlying Islands, and 326 Indian reservations. The United States is also in free association with three Pacific Island sovereign states: the Federated States of Micronesia, the Marshall Islands, and the Republic of Palau. It is the world's third-largest country by both land and total area. It shares land borders with Canada to its north and with Mexico to its south and has maritime borders with the Bahamas, Cuba, Russia, and other nations. With a population of over 333 million, it is the most populous country in the Americas and the third most populous in the world. The national capital of the United States is Washington, D.C. and its most populous city and principal financial center is New York City. Paleo-Americ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
New Keynesian Economics
New Keynesian economics is a school of macroeconomics that strives to provide microfoundations, microeconomic foundations for Keynesian economics. It developed partly as a response to criticisms of Keynesian macroeconomics by adherents of new classical macroeconomics. Two main assumptions define the New Keynesian approach to macroeconomics. Like the New Classical approach, New Keynesian macroeconomic analysis usually assumes that households and firms have rational expectations. However, the two schools differ in that New Keynesian analysis usually assumes a variety of market failures. In particular, New Keynesians assume that there is imperfect competition in price and wage setting to help explain why prices and wages can become "Sticky (economics), sticky", which means they do not adjust instantaneously to changes in economic conditions. Wage and price stickiness, and the other market failures present in New Keynesian Model (macroeconomics), models, imply that the economy may ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Consumption Smoothing
Consumption smoothing is an economic concept for the practice of optimizing a person's standard of living through an appropriate balance between savings and consumption over time. An optimal consumption rate should be relatively similar at each stage of a person's life rather than fluctuate wildly. Luxurious consumption at an old age does not compensate for an impoverished existence at other stages in one's life. Since income tends to be hump-shaped across an individual's life, economic theory suggests that individuals should on average have low or negative savings rate at early stages in their life, high in middle age, and negative during retirement. Although many popular books on personal finance advocate that individuals should at all stages of their life set aside money in savings, economist James Choi states that this deviates from the advice of economists. Expected utility model The graph below illustrates the expected utility model, in which U(c) is increasing in and con ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
