This paper elaborates equilibrium properties of contract labor markets when cost barriers limit labor mobility in response to demand and productivity shifts. Unemployment is sustained because the marginal value of labor is not equated across all firms; however the equilibrium contract optimally allocates a worker's time between market and nonmarket uses, given transactions cost-mobility constraints. Contracts provide full unemployment insurance for risks that are diversifiable by pooling among firms. Nondiversifiable (macro) risks are only partially shifted,largely through self-insurance (contingency saving). Increasing diversifiable risk has social value, similar to the value of an option. Increasing nondiversifiable risk has negative value because it reduces lifetime consumption. The main empirical implication of contract theory is shown to be closely related to the permanent income hypothesis and establishes linkages between labor activities and consumption behavior. It is atheory of consumption rigidity rather than wage rigidity. Another empirical implication is that unemployment incidence is proportional to comparative advantage in normarket production. Layoffs are ordered by workers' relative productivity in nonmarket compared with market sectors. The theory is used to analyze some features of the U.S. employment system. Its empirical support is briefly reviewed.