' (also spelled '; () is a

Latin Latin (, or , ) is a classical language belonging to the Italic branch of the Indo-European languages. Latin was originally a dialect spoken in the lower Tiber area (then known as Latium) around present-day Rome, but through the power of the ...

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 about a

causal Causality (also referred to as causation, or cause and effect) is influence by which one event, process, state, or object (''a'' ''cause'') contributes to the production of another event, process, state, or object (an ''effect'') where the cau ...

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 ...

, or

logical Logic is the study of correct reasoning. It includes both formal and informal logic. Formal logic is the science of deductively valid inferences or of logical truths. It is a formal science investigating how conclusions follow from premises ...

relation between two states of affairs is ''ceteris paribus'' if it is acknowledged that the statement, although usually accurate in expected conditions, can fail because of, or the relation can be abolished by, intervening factors. chapter 2 A ''ceteris paribus'' assumption is often key to scientific inquiry, because scientists seek to eliminate factors that perturb a relation of interest. Thus

epidemiologist Epidemiology is the study and analysis of the distribution (who, when, and where), patterns and risk factor, determinants of health and disease conditions in a defined population. It is a cornerstone of public health, and shapes policy decision ...

s, for example, may seek to control

independent variable Dependent and independent variables are variables in mathematical modeling, statistical modeling and experimental sciences. Dependent variables receive this name because, in an experiment, their values are studied under the supposition or demand ...

s as factors that may influence

dependent variables Dependent and independent variables are variables in mathematical modeling, statistical modeling and experimental sciences. Dependent variables receive this name because, in an experiment, their values are studied under the supposition or demand ...

—the outcomes of interest. Likewise, in

scientific modeling Scientific modelling is a scientific activity, the aim of which is to make a particular part or feature of the world easier to understand, define, quantify, visualize, or simulate by referencing it to existing and usually commonly accepted k ...

, simplifying assumptions permit illustration of concepts considered relevant to the inquiry. An example in economics is "If the price of milk falls, ceteris paribus, the demand for milk will rise." This means that, if other factors, such as deflation, pricing objectives, utility, and marketing methods, do not change, the decrease in the price of milk will lead to an increase in demand for it. In the philosophy of science, there is debate about ''ceteris paribus'' statements. In the

logical empiricist Logical positivism, later called logical empiricism, and both of which together are also known as neopositivism, is a movement in Western philosophy whose central thesis was the verification principle (also known as the verifiability criterion o ...

view,

fundamental physics In physics, the fundamental interactions, also known as fundamental forces, are the interactions that do not appear to be reducible to more basic interactions. There are four fundamental interactions known to exist: the gravitational and electrom ...

tends to state universal laws, whereas other sciences, such as biology, and social sciences, such as economics and psychology, tend to state laws that hold true in normal conditions but have exceptions: ''ceteris paribus'' laws (''cp laws'').Alexander Reutlinger, Gerhard Schurz & Andreas Hüttemann
"Ceteris paribus laws"
in Edward N Zalta, ed, ''The Stanford Encyclopedia of Philosophy'', Spring 2014 edn. The focus on universal laws is a criterion distinguishing fundamental physics as

fundamental Fundamental may refer to: * Foundation of reality * Fundamental frequency, as in music or phonetics, often referred to as simply a "fundamental" * Fundamentalism, the belief in, and usually the strict adherence to, the simple or "fundamental" idea ...

, whereas cp laws are predominant in most other sciences as

special science Special sciences are those sciences other than fundamental physics. In this view, chemistry, biology, and neuroscience—indeed, all sciences except fundamental physics—are special sciences. The status of the special sciences, and their relati ...

s, whose laws hold in special cases. This distinction assumes a

view of science. It does not readily apply in a mechanistic understanding of scientific discovery. There is reasonable disagreement as to whether mechanisms or laws are the appropriate model; mechanisms are the favored method.Glennan, S. (2014). Mechanisms. In M. Curd & S. Psillos (eds.), ''The Routledge companion to philosophy of science'' (2nd ed., pp. 420–428). New York: Routledge. Another possibility if we assume ''ceteris paribus'' in a scenario is the tendency to ignore many important factors that may play even greater roles in the measure of the dependent variable. Some assumptions tend to be highly unrealistic and can lead to wrong beliefs among scientists.

Economics

Economics' ''ceteris paribus'' conditions include: * The number of consumers in the market * Consumer tastes or preferences * Prices of substitute goods * Consumer price expectations * Personal income

Interpretation

One of the disciplines in which ''ceteris paribus'' clauses are most widely used is

economics Economics () is the social science that studies the Production (economics), production, distribution (economics), distribution, and Consumption (economics), consumption of goods and services. Economics focuses on the behaviour and intera ...

, in which they are employed to simplify the formulation and description of economic outcomes. When using ''ceteris paribus'' in economics, one assumes that all other variables except those under immediate consideration are held constant. For example, it can be predicted that if the price of

beef Beef is the culinary name for meat from cattle (''Bos taurus''). In prehistoric times, humankind hunted aurochs and later domesticated them. Since that time, numerous breeds of cattle have been bred specifically for the quality or quantity ...

''increases''—''ceteris paribus''—the quantity of beef demanded by buyers will ''decrease''. In this example, the clause is used to operationally describe everything surrounding the relationship between both the ''price'' and the ''quantity demanded'' of an

ordinary good An ordinary good is a microeconomic concept used in consumer theory. It is defined as a good which creates an increase in quantity demanded when the price for the good drops or conversely a decrease in quantity demanded if the price for the good in ...

. This operational description intentionally ignores both known and unknown factors that may also influence the relationship between price and quantity demanded, and thus to assume ''ceteris paribus'' is to assume away any interference with the given example. Such factors that would be intentionally ignored include: a change in the price of substitute goods, (e.g., the price of pork or lamb); a change in the level of

risk aversion In economics and finance, risk aversion is the tendency of people to prefer outcomes with low uncertainty to those outcomes with high uncertainty, even if the average outcome of the latter is equal to or higher in monetary value than the more ce ...

among buyers (e.g., due to an increase in the fear of

mad cow disease Bovine spongiform encephalopathy (BSE), commonly known as mad cow disease, is an incurable and invariably fatal neurodegenerative disease of cattle. Symptoms include abnormal behavior, trouble walking, and weight loss. Later in the course of t ...

); and a change in the level of overall demand for a good regardless of its current price (e.g., a societal shift toward

vegetarianism Vegetarianism is the practice of abstaining from the consumption of meat (red meat, poultry, seafood, insects, and the flesh of any other animal). It may also include abstaining from eating all by-products of animal slaughter. Vegetarianism may ...

). The clause is often loosely translated as "holding all else constant." It does not imply that no other things will in fact change; rather, it isolates the effect of one particular change. Holding all other things constant is directly analogous to using a

partial derivative In mathematics, a partial derivative of a function of several variables is its derivative with respect to one of those variables, with the others held constant (as opposed to the total derivative, in which all variables are allowed to vary). Part ...

calculus Calculus, originally called infinitesimal calculus or "the calculus of infinitesimals", is the mathematical study of continuous change, in the same way that geometry is the study of shape, and algebra is the study of generalizations of arithm ...

rather than a

total derivative In mathematics, the total derivative of a function at a point is the best linear approximation near this point of the function with respect to its arguments. Unlike partial derivatives, the total derivative approximates the function with resp ...

, and to running a

regression Regression or regressions may refer to: Science * Marine regression, coastal advance due to falling sea level, the opposite of marine transgression * Regression (medicine), a characteristic of diseases to express lighter symptoms or less extent ( ...

containing multiple variables rather than just one in order to isolate the individual effect of one of the variables. Ceteris paribus is an extension of scientific modeling. The scientific method is built on identifying, isolating, and testing the impact of an independent variable on a dependent variable. One thing to note is that since economic variables can only be isolated in theory and not in practice, ceteris paribus can only ever highlight tendencies, not absolutes.

Characterization given by Alfred Marshall

The clause is used to consider the effect of some causes in isolation, by assuming that other influences are absent.

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 ...

expressed the use of the clause as follows:

Two uses

The above passage by Marshall highlights two ways in which the ''ceteris paribus'' clause may be used: The one is ''hypothetical'', in the sense that some factor is assumed fixed in order to analyse the influence of another factor in isolation. This would be hypothetical isolation. An example would be the hypothetical separation of 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 pref ...

and the

substitution effect In economics and particularly in consumer choice theory, the substitution effect is one component of the effect of a change in the price of a good upon the amount of that good demanded by a consumer, the other being the income effect. When a g ...

of a price change, which actually go together. The other use of the ''ceteris paribus'' clause is to see it as a means for obtaining an approximate solution. Here it would yield a substantive isolation. Substantive isolation has two aspects: temporal and causal. Temporal isolation requires the factors fixed under the ''ceteris paribus'' clause to actually move so slowly relative to the other influence that they can be taken as practically constant at any point in time. So, if

spreads very slowly, inducing a slow decline in the demand for beef, and the market for beef clears comparatively quickly, we can determine the price of beef at any instant by the intersection of supply and demand, and the changing demand for beef will account for the price changes over time ( Temporary Equilibrium Method). The other aspect of substantive isolation is causal isolation: those factors frozen under a ''ceteris paribus'' clause should not significantly be affected by the processes under study. If a change in government policies induces changes in consumers' behaviour on the same time scale, the assumption that consumer behaviour remains unchanged while policy changes is inadmissible as a substantive isolation (

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 historic ...

Notes

References

* Marshall, A. 1920. Principles of economics. Vol. 1. 8th ed. London: Macmillan.

External links

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{{DEFAULTSORT:Ceteris Paribus Latin logical phrases Latin philosophical phrases Philosophy of science Causality Philosophy of economics