"Restrictions that general equilibrium theory place upon average returns are found to be strongly violated by the U.S. data in the 1889-1978 period. This result is robust to model specification and measurement problems. We conclude that equilibrium models which are not Arrow-Debreu economies are...

"This paper reviews the role of micro non-convexities in the study of business cycles. One important non-convexity arises because an individual can work only one workweek length in a given week. The implication of this non-convexity is that the aggregate intertemporal elasticity of labor supply...