Published in

Econometric Society, Econometrica, 3(74), p. 585-610

DOI: 10.1111/j.1468-0262.2006.00675.x

Links

Tools

Export citation

Search in Google Scholar

The Limits of ex post Implementation

Journal article published in 2006 by Philippe Jehiel, Moritz Meyer ter-Vehn, William R. Zame, Moritz Meyer-Ter-Vehn, Benny Moldovanu, William B. Zame
This paper is available in a repository.
This paper is available in a repository.

Full text: Download

Red circle
Preprint: archiving forbidden
Red circle
Postprint: archiving forbidden
Red circle
Published version: archiving forbidden
Policy details
Data provided by SHERPA/RoMEO

Abstract

The sensitivity of Bayesian implementation to agents' beliefs about others suggests the use of more robust notions of implementation such as ex post implementation, which requires that each agent's strategy be optimal for every possible realization of the types of other agents. We show that the only deterministic social choice functions that are ex post implementable in generic mechanism design frameworks with multidimensional signals, interdependent valuations, and transferable utilities are constant functions. In other words, deterministic ex post implementation requires that the same alternative must be chosen irrespective of agents' signals. The proof shows that ex post implementability of a nontrivial deterministic social choice function implies that certain rates of information substitution coincide for all agents. This condition amounts to a system of differential equations that are not satisfied by generic valuation functions. Copyright The Econometric Society 2006.