We study dynamic moral hazard where principal and agent are symmetrically uncertain about job difficulty. Since effort is unobserved, shirking leads the principal to believe that the job is hard, increasing the agent's continuation value. So deterring shirking requires steeper incentives, which...

We study dynamic moral hazard, with symmetric ex ante uncertainty and learning. Unlike Holmstrom's career concerns model, uncertainty pertains to the difficulty of the job rather than the general talent of the agent, so that contracts are required to provide incentives. Since effort is privately...

We study contracting between a consumer and an expert. The expert can invest in diagnosis to obtain a noisy signal about whether a low-cost service is sufficient or whether a high-cost treatment is required to solve the consumer’s problem. This involves moral hazard because diagnosis effort...

This paper analyzes the impact of labor market competition and skill-biased technical change on the structure of compensation. The model combines multitasking and screening, embedded into a Hotelling-like framework. Competition for the most talented workers leads to an escalating reliance on...

We study the effects of improvements in eBay's rating mechanism on seller exit and continuing sellers' behavior. Following a large sample of sellers over time, we exploit the fact that the rating mechanism was changed to reduce strategic bias in buyer rating. That improvement did not lead to...

We characterize optimal incentive contracts in a moral hazard framework extended in two directions. First, after effort provision, the agent is free to leave and pursue some ex-post outside option. Second, the value of this outside option is increasing in effort, and hence endogenous. Optimal...

We examine a "Rotten Kid" model (Becker 1974) where a player with social preferences interacts with an egoistic player. We assume that social preferences are intention-based rather than outcome-based. In a very general multi-stage setting we show that any equilibrium must involve mutually unkind...

A principal should hire one agent to perform two sequential tasks when the tasks are conflicting (i.e., a first-stage success makes second-stage effort less effective), while she should hire two different agents when the tasks are synergistic.

The government wants two tasks to be performed. In each task, unobservable effort can be exerted by a wealth-constrained private contractor. If the government faces no binding budget constraints, it is optimal to bundle the tasks. The contractor in charge of both tasks then gets a bonus payment...

This paper analyses the relation between authority and incentives. It extends the standard principal--agent model by a project selection stage in which the principal can either delegate the choice of project to the agent or keep the authority. The agent's subsequent choice of effort depends both...