Social and Behavioral Sciences Commons^™

Subgame Perfect Implementation Under Information Perturbations, Takashi Kunimoto, Drew Fudenberg, Takashi Kunimoto, Oliver Tercieux

Research Collection School Of Economics

We consider the robustness of extensive form mechanisms to deviations from common knowledge about the state of nature, which we refer to as information perturbations. First, we show that even under arbitrarily small information perturbations the Moore-Repullo mechanism does not yield (even approximately) truthful revelation and that in addition the mechanism has sequential equilibria with undesirable outcomes. More generally, we prove that any extensive form mechanism is fragile in the sense that if a non-Maskin monotonic social objective can be implemented with this mechanism, then there are arbitrarily small information perturbations under which an undesirable sequential equilibrium also exists. Finally, …