We study how best to reward innovators whose work builds on earlier innovations. Incentives to innovate are obtained by offering innovators the opportunity to profit from their innovations. Since innovations compete, awarding rights to one innovator reduces the value of the rights to prior...

We study optimal incentives in a principal-agent problem in which the agent's outside option is determined endogenously in a competitive labor market. In equilibrium, strong performance increases the agent's market value. When this value becomes sufficiently high, the threat of the agent's...

than that implied by Hopenhayn and Nicolini (1997).

We present evidence that fraudulent collection of unemployment benefits by workers who are gainfully employed is the most relevant incentive problem for the design of unemployment insurance. We show how to efficiently use a combination of tax/subsidy and monitoring to prevent such fraud. The...

We study taxation as an alternative to intermediation in a Diamond-Dybvig economy with a private ex post retrade market and with private ex ante investment. The possibility of private investment imposes an additional constraint on the social planner beyond resource feasibility and incentive...

Stock price bubbles are often on productive assets and occur in a sector of the economy. In addition, their occurence is often accompanied by credit booms. Incorporating these features, we provide a two-sector endogenous growth model with credit-driven stock price bubbles. Bubbles have a credit...

equilibria in models with heterogeneous agents and market frictions. This method is based upon a convergent operator over an expanded set of state variables. The fixed point of this operator defines the set of all Markovian equilibria. We study approximation properties of the operator as well as...

This paper provides an explanation for momentum and reversal in stock returns within a rational expectations framework in which investors are heterogeneous in their information and investment opportunities. We assume that informed agents privately receive advance information about company...

This paper develops a real options model to study the interaction between industry structure and takeover activity. In an asymmetric industry equilibrium, firms have an endogenous incentive to merge when restructuring decisions are motivated by operating and strategic benefits. The model...

We provide an infinite-horizon model of a production economy with bubbles, in which firms meet stochastic investment opportunties and face credit constraints. Capital is not only an input for production, but also serves as collateral. We show that bubbles on this reproducible asset may arise,...