Instrumental variables (IV) are a common means to identify treatment effects. But standard IV methods do not allow us to unpack the complex treatment effects that arise when a treatment and its outcome together cause a second outcome of interest. For example, IV methods have been used to show...

This paper offers and tests a theory of training whereby workers do not pay for general training they receive. The crucial ingredient in our model is that the current employer has superior information about the worker's ability relative to other firms. This informational advantage gives the...