This paper presents a model of cumulative innovation in which 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. Monopoly power is a scarce resource to be allocated...

We consider a directed search model in which workers differ in productivity. Productivity becomes observable to firms after assessing their workers on the job, but it is not verifiable. Firms with vacancies choose between posting a noncontingent wage and leaving wages subject to bargaining with...