Rational choice theory: Necessary but not sufficient.

I I I ! I ABSTRACT: A case is presented for supplementing the standard theory of rational choice, according to which subjects maximize reinforcement, with a theory arising from experiments on animal and human behavior. Data from these experiments suggest that behavioral allocation comes into equilibrium when it equalizes the average re- inforcement rates earned by all active response alternatives in the subject's choice set. This principle, called the matching law, deviates from reinforcement maximization in some, but not all, environments. Many observed devia- tions from reinforcement maximization are reasonably well explained by conformity to the matching law. The theory of rational choice fails as a description of actual behavior, but it remains unequaled as a normative theory. It tells us how we should behave in order to maximize reinforcement, not how we do behave.