There are two parts in our note. The first highlights Leo's contribution that earned him the Nobel prize in economics, from a personal point of view. The second discusses further questions that can naturally be addressed using Leo's conceptual framework

It is well-known that the ability of the Vickrey-Clarke-Groves (VCG) mechanism to implement efficient outcomes for private value choice problems does not extend to interdependent value problems. When an agent's type affects other agents' utilities, it may not be incentive compatible for him to...