We characterize the boundaries of the set of transfers (extremal transfers) implementing a given allocation rule without imposing any assumptions on the agentʼs type space or utility function besides quasi-linearity. Exploiting the concept of extremal transfers allows us to obtain an exact...

We provide sufficient conditions for the validity of the first-order approach for two-period dynamic moral hazard problems where the agent can save and borrow secretly. The first-order approach is valid if the following conditions hold: (i) the agent has non-increasing absolute risk aversion...