[I examine the effects of price discrimination on the equilibrium prices, number of firms, and level of total surplus in a monopolistically competitive market. The main finding is that uniform pricing is more (less) efficient than is price discrimination when the purchases made by the consumers who are discriminated against constitute a small (large) proportion of the total purchases.]

The authors examine the effects of renegotiation in an agency relationship. They show how renegotiation affects (1) the set of actions the principal can induce the agent to take and (2) the cost of implementing a given action. The authors show that, when the principal receives an unverifiable signal of the agent's action, renegotiation can improve welfare. This result stands in contrast to earlier findings that renegotiation lowers welfare when the principal receives no signal about the agent's action prior to renegotiation.