We define the empirical content of an economic theory as the least restrictive observationally equivalent theory. We show that the empirical content of a theory is captured by a certain kind of axiomatization, with axioms that are universal negations of conjunctions of atomic formulae.

We consider several ordinal formulations of submodularity, defined for arbitrary binary relations on lattices. Two of these formulations are essentially due to Kreps [Kreps, D.M., 1979. A representation theorem for "Preference for Flexibility". Econometrica 47 (3), 565-578] and one is a...

We study the behavioral denition of complementary goods: if the price of one good increases, demand for a complementary good must decrease. We obtain its full implications for observable demand behavior (its testable implications), and for the consumer's underlying preferences. We characterize...

We develop observable restrictions of well-known theories of bargaining over money. We suppose that we observe a finite data set of bargaining outcomes, including data on allocations and disagreement points, but no information on utility functions. We ask when a given theory could generate the...

We study the problem of risk sharing within a household or syndicate. A household shares risky prospects using a social welfare functional. We characterize the social welfare functionals such that the household is collectively less risk averse than each member, and satisfies the Pareto principle...

We present a nonparametric "revealed-preference test" for gross substitutes in demand for two goods. (JEL D01, D11)