This paper develops and structurally estimates a learning model in which firms acquire information about workers' ability by observing their performance over time. A firm consists of a collection of jobs which differ in the informational content of performance, as measured by the dispersion in...

We analyze a dynamic principal-agent model where an infinitely-lived principal faces a sequence of finitely-lived agents who differ in their ability to produce output. The ability of an agent is initially unknown to both him and the principal. An agent's effort affects the information on ability...