Rational choice theory, also known as choice theory or rational action theory, is a framework for understanding and often formally modeling social and economic behavior. The basic premise of rational choice theory is that aggregate social behavior results from the behavior of individual actors, each of whom is making their individual decisions. The theory also focuses on the determinants of the individual choices (methodological individualism).
Rational choice theory then assumes that an individual has preferences among the available choice alternatives that allow them to state which option they prefer. These preferences are assumed to be complete (the person can always say which of two alternatives they consider preferable or that neither is preferred to the other) and transitive (if option A is preferred over option B and option B is preferred over option C, then A is preferred over C). The rational agent is assumed to take account of available information, probabilities of events, and potential costs and benefits in determining preferences, and to act consistently in choosing the self-determined best choice of action.
Rationality is widely used as an assumption of the behavior of individuals in microeconomic models and analyses and appears in almost all economics textbook treatments of human decision-making. It is also used in political science,sociology, and philosophy. A particular version of rationality is instrumental rationality, which involves seeking the most cost-effective means to achieve a specific goal without reflecting on the worthiness of that goal. Gary Becker was an early proponent of applying rational actor models more widely. Becker won the 1992 Nobel Memorial Prize in Economic Sciences for his studies of discrimination, crime, and human capital.
The concept of rationality used in rational choice theory is different from the colloquial and most philosophical use of the word. Colloquially, "rational" behaviour typically means "sensible", "predictable", or "in a thoughtful, clear-headed manner." Rational choice theory uses a narrower definition of rationality. At its most basic level, behavior is rational if it is goal-oriented, reflective (evaluative), and consistent (across time and different choice situations). This contrasts with behavior that is random, impulsive, conditioned, or adopted by (unevaluative) imitation.