TY - JOUR
T1 - Ex post implementation
AU - Bergemann, Dirk
AU - Morris, Stephen
N1 - Funding Information:
This research has been supported by NSF Grants #SES-0095321 and #SES-0518929. Corresponding author. E-mail addresses: [email protected] (D. Bergemann), [email protected] (S. Morris). 1 See Dasgupta and Maskin (2000), Perry and Reny (2002) and Bergemann and Välimäki (2002) among many others.
Funding Information:
The first author gratefully acknowledges support through a DFG Mercator Research Professorship at the Center of Economic Studies at the University of Munich. We benefited from discussions with Jeff Ely, Matt Jackson, Andy Postlewaite, Phil Reny, Mike Riordan and Roberto Ser- rano. We would like to thank seminar audiences at California Institute of Technology, Columbia University, Cornell University, New York University, Nuffield College, Princeton University, University of Michigan, the Paris Roy seminar, the Cowles Foundation Conference on “Robust Mechanism Design” and the Second World Congress of the Game Theory Society for helpful comments. Parts of this paper were reported in early drafts of our work on Robust Mechanism Design (Bergemann and Morris, 2001).
PY - 2008/7
Y1 - 2008/7
N2 - We analyze the problem of fully implementing a social choice set in ex post equilibrium. We identify an ex post monotonicity condition that is necessary and-in economic environments-sufficient for full implementation in ex post equilibrium. We also identify an ex post monotonicity no veto condition that is sufficient. Ex post monotonicity is satisfied in all single crossing environments with strict ex post incentive constraints. We show by means of two classic examples that ex post monotonicity does not imply nor is it implied by Maskin monotonicity. The single unit auction with interdependent valuations is shown to satisfy ex post monotonicity but not Maskin monotonicity. We further describe a Pareto correspondence that fails ex post monotonicity but satisfies Maskin monotonicity.
AB - We analyze the problem of fully implementing a social choice set in ex post equilibrium. We identify an ex post monotonicity condition that is necessary and-in economic environments-sufficient for full implementation in ex post equilibrium. We also identify an ex post monotonicity no veto condition that is sufficient. Ex post monotonicity is satisfied in all single crossing environments with strict ex post incentive constraints. We show by means of two classic examples that ex post monotonicity does not imply nor is it implied by Maskin monotonicity. The single unit auction with interdependent valuations is shown to satisfy ex post monotonicity but not Maskin monotonicity. We further describe a Pareto correspondence that fails ex post monotonicity but satisfies Maskin monotonicity.
KW - Ex post equilibrium
KW - Implementation
KW - Interdependent values
KW - Single crossing
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U2 - 10.1016/j.geb.2006.10.006
DO - 10.1016/j.geb.2006.10.006
M3 - Article
AN - SCOPUS:44649180491
SN - 0899-8256
VL - 63
SP - 527
EP - 566
JO - Games and Economic Behavior
JF - Games and Economic Behavior
IS - 2
ER -