Parallelism: Propositions about the behavior of individuals and the performance of institutions that have been tested in laboratory microeconomies ap… - Vernon L. Smith

In economics the tendency of theory to lag behind observation seems to be endemic, and, as theorists, few of us consider this to be a "terrible state." But as noted by Lakatos (1978, p. 6), "where theory lags behind the facts, we are dealing with miserable degenerating research programmes."

Theory should be ever more demanding of our empirical resources. Simultaneously, data should be ever more demanding of the empirical relevance of theory and of the theorist's expertise in working imaginatively on problems of the world, rather than on stylized problems of the imagination.

Nonsatiation (Smith, 1976a). Given a costless choice be ween two alternatives which differ only in that the first yields more of the reward medium (e.g., currency) than the second, the first will always be chosen (preferred) over the second by an autonomous individual, i.e., utility U(M) is a monotone increasing function of the reward medium.