Ceteris paribus (also spelled caeteris paribus) (Classical ) 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 about a ontic, epistemic, Morality, or inductive logic 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 , for example, may seek to control independent variables as factors that may influence dependent variables—the outcomes of interest. Likewise, in scientific modeling, 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 quantity of milk demanded 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.
Economist Alfred Marshall had significant effects on the popularity for the ceteris paribus clause in the 19th century. It was his support to economics where he promoted partial equilibrium analysis, claiming that this analysis, and similar analysis’ hold due to the ceteris paribus clauses.
The importance that ceteris paribus has brought to economics is not only found in histographical interests, but is still vital to economists today, seen frequently in textbooks.
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 among buyers (e.g., due to an increase in the fear of mad cow disease); and a change in the level of overall demand for a good regardless of its current price (e.g., a societal shift toward vegetarianism).
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 calculus rather than a total derivative, and to running a regression 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.
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 vegetarianism 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).
Ceteris Paribus is also inherently limited by what has been learned in complexity science about those situations which are highly affected by interconnections. Amid highly connected situations, a change to any one variable will change all others. In this way, when these complex connections are active, it is not possible in reality to hold all other values constant. Complex interconnected reality is not only common in physical and natural sciences but is of great influence in most socio-economic sciences.
Interpretation
Alfred Marshall's characterization
Two uses
Applications
Limitation of ceteris paribus
/ref>
See also
Notes
External links
|
|