We study optimal direct mechanisms for a credence goods expert who can be altruistic or spiteful. The expert has private information about her distributional preferences and possibly also about her customer's needs. We introduce a method that allows the customer to offer separate contracts to...

Governments must usually take policy decisions with an imperfect knowledge of the economic actors' type or the actors' effort level. These issues are addressed within the framework of classic adverse selection or moral hazard models. I discuss in this paper how would the government’s and the...