Strategy-proofness, requiring that truth-telling be a dominant strategy, is a standard concept in social choice theory. However, this concept has serious drawbacks. In particular, many strategy-proof mechanisms have multiple Nash equilibria, some of which produce the wrong outcome. A possible...

One of the most salient issues faced by platforms like newspapers and credit card issuers is that users are heterogeneous in the value they bring to other users or to the platform. We develop a model with multi-dimensional heterogeneity where a monopoly platform chooses (price or non-price)...

Building upon the classical concept of Holder continuity and the notion of "continuous implementation"introduced in Oury and Tercieux (2009), we define Hölder continuous implementation. We show that, under a richness assumption on the payo proles (associated with outcomes), the following full...

We study the mechanism-design problem of guaranteeing desirable performances whenever agents are rational in the sense of not playing weakly dominated strategies. We first provide an upper bound for the best performance we can guarantee among all feasible mechanisms. We then prove the bound to...