A principal wants an agent to complete a project. The agent undertakes unobservable effort, which affects in each period the probability that the project is completed. We characterize the contracts that the principal sets, with and without commitment. With full commitment, the contract involves...

The paper investigates the interaction between dynamic forms of incentive mechanisms (patent systems) and dynamic forms of problems (adaptations of pests and pathogens). Since biological problems recur, the design of the incentive mechanism must take into consideration: a) the need for...