The US economy has undergone a number of puzzling changes in recent decades. Large firms now account for a greater share of economic activity, new firms are being created at a slower rate, and workers are getting paid a smaller share of GDP. This paper shows that changes in population growth...

This paper characterizes the effects of market size on the size distribution of establishments for thirteen retail trade industries across 225 U.S. cities. In most industries we examine, establishments are larger in larger cities. Models of large-group competition in which markups fall after...

This paper characterizes the effects of market size on the size distribution of establishments for thirteen retail trade industries across 225 U.S. cities. In most industries we examine, establishments are larger in larger cities. Models of large-group competition in which markups fall after...

Entrepreneurs bear substantial risk, but empirical evidence shows no sign of a positive premium. This paper develops a theory of endogenous entrepreneurial risk taking that explains why self-financed entrepreneurs may find it optimal to invest in risky projects offering no risk premium. The...

This paper presents a model of cumulative innovation where firms are heterogeneous in their research ability. We study the optimal reward policy when the quality of the ideas and their subsequent development effort are private information. The optimal assignment of property rights must...

When innovations are heterogeneous, it may be advantageous to provide a variety of patents. By trading off patent breadth for length, it is possible that fees are not needed in the optimal policy. We present two examples. The first is a quality-ladder model, in which innovations benefit society...

This paper considers the design of an optimal unemployment insurance system. The problem is modeled as a repeated principal-agent problem involving a risk-averse agent--the unemployed worker--and a risk-neutral principal, which cannot monitor the agent's search effort. The optimal long-term...

Over the last few years, the debate on labor market reform has been at the center of economic policy debate in Argentina. This debate has been fueled by the sustained growth in the unemployment rate observed during the decade. One of the major targets of the attack on labor market regulation has...

We study a multiperiod principal-agent problem with moral hazard in which effort is persistent: the agent is required to exert effort only in the initial period of the contract, and this effort determines the conditional distribution of output in the following periods. We provide a...