This paper provides an explanation of involuntary umemployment arising as a consequence of asymmetric information between firms and workers. Involuntary unemployment is defined as a situation where ex post gains to trade exist. A model of labor contracts is developed where the allocations are not ex post optimal. It is shown that inferiority of leisure is a necessary and sufficient condition for the existence of involuntary unemployment.

V. V. Chari, Ravi Jagannathan, Larry Jones; Price Stability and Futures Trading in Commodities*, The Quarterly Journal of Economics, Volume 105, Issue 2, 1

In standard monetary policy approaches, interest-rate rules often produce indeterminacy. A sophisticated policy approach does not. Sophisticated policies depend on the history of private actions, government policies, and exogenous events and can differ on and off the equilibrium path. They can uniquely implement any desired competitive equilibrium. When interest rates are used along the equilibrium path, implementation requires regime-switching. These results are robust to imperfect information. Our results imply that the Taylor principle is neither necessary nor sufficient for unique implementation. They also provide a direction for empirical work on monetary policy rules and determinacy.