CFDP 1666R

Robust Implementation in General Mechanisms


Publication Date: June 2008

Revision Date: January 2009

Pages: 41


A social choice function is robustly implemented if every equilibrium on every type space achieves outcomes consistent with it. We identify a robust monotonicity condition that is necessary and (with mild extra assumptions) sufficient for robust implementation.

Robust monotonicity is strictly stronger than both Maskin monotonicity (necessary and almost sufficient for complete information implementation) and ex post monotonicity (necessary and almost sufficient for ex post implementation). It is equivalent to Bayesian monotonicity on all type spaces.


Mechanism design, Implementation, Robustness, Common knowledge, Interim equilibrium, Dominant strategies

JEL Classification Codes:  C79, D82

See CFP: 1316