Ceteris paribus

Ceteris paribus (also spelled caeteris paribus) (Classical Latin pronunciation: [ˈkeːtɛ.riːs ˈpa.rɪ.bʊs]) 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 causal, empirical, moral, or logical 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. A ceteris paribus assumption is often key to scientific inquiry, because scientists seek to eliminate factors that perturb a relation of interest. Thus epidemiologists, 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.