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 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.

In games with strict strategic complementarities, properly mixed Nash equilibria--equilibria that are not in pure strategies--are unstable for a broad class of learning dynamics.

In games with strict strategic complementarities, properly mixed Nash equilibria--equilibria that are not in pure strategies--are unstable for a broad class of learning dynamics.