How did it become possible to exchange apparently valueless pieces of paper for goods? This paper provides an equilibrium account of the transition between barter and fiat-money regimes. The explanation relies on the intervention of a self-interested government which must be able to promise credibly to limit the issue of money. To achieve credibility, the government must offset the benefits of seigniorage by internalizing some of the macroeconomic externalities generated by the issue of fiat money. The government's patience and the extent of its involvement in the economy are key determinants of whether the transition can be accomplished.

In the United States, black workers earn less than their white counterparts and have higher rates of unemployment. Empirical work indicates that most of this wage gap is accounted for by differences in cognitive skills that emerge at an early age. In this paper, we demonstrate that the same is not true for black-white disparity in unemployment. A large unexplained unemployment differential motivates the paper's second contribution—a potential theoretical explanation. This explanation is built around a model that embeds statistical discrimination into the subjective worker evaluation process that lies at the root of the efficiency-wage theory of equilibrium unemployment.

From the standpoint of economic theory, the difficulty in regulating workers' performance distinguishes labor markets from commodity markets. Commodities do not respond to incentives. Workers, in contrast, can quit, steal, be hung over, refuse to cooperate with other workers, or generally work at low effort levels. Since direct monitoring is often costly and unreliable, it may not be the profit-maximizing solution to this problem. Economists have discussed various schemes to make productive behavior incentive-compatible for workers. The most frequently discussed schemes fall into two broad categories: efficiency wages and deferred compensation or bonding schemes.! These schemes have been suggested as explanations for a wide variety of labormarket features that appear anomalous from the conventional supply-and-demand perspective. Efficiency-wage models can generate equilibria in which there is involuntary unemployment and in which identical workers are paid different wages in jobs that are otherwise equally attractive. George A. Akerlof and Janet L. Yellen (1985) have argued that they can provide an important component of a model of business cycles. Deferred-compensation schemes have been proposed as explanations for upward-sloping age-earnings profiles, mandatory retirement, pensions, and hierarchical (tournament) promotion structures.2 Because bonding is costless to firms, efficiency-wage and bonding strategies are often viewed as mutually incompatible; profit-maximizing firms should offer efficiency wages only in situations where bonding is impossible. One widely held view argues that in labor markets where agency issues arise, these problems are effectively solved by various bonding arrangements (and moreover, that this observation helps to explain otherwise peculiar features of some labor markets, as mentioned above). It follows that efficiency wages do not generally exist. Proponents of efficiency-wage theory argue that there is considerable evidence of widespread agency problems (e.g., large expenditures by many firms on monitoring) and that there are barriers to the use of bonds, notably moral hazard on the part of firms or legal constraints. Efficiency wages cannot therefore be ruled out a priori as an equilibrium solution to these agency problems.3 In this paper we study these issues surrounding efficient worker compensation in a framework that allows heterogeneity among firms and integrates the financial and