This chapter, originally written as a consequence of the terrorist attacks of September 11, 2001, provides an elementary, everyday introduction to the concepts of risk and insurance. Conceptually, risk has two dimensions: a potential loss, and the chance of that loss being realized. People can,...

We consider a general economy, where agents have private information about their types. Types can be multi-dimensional and potentially interdependent. We show that, if the interim distribution of types is common knowledge (the exact number of agents for each type is known), then a mechanism...

I develop an overlapping-generations framework in which changes in lending standards generate endogenous cycles. In my economy, entrepreneurs who are privately informed about the quality of their projects need to borrow funds. Intermediaries screen entrepreneurs both through the amount of...