The robustness of robust implementation

摘要

Abstract We show that a mechanism that robustly implements optimal outcomes in a one-dimensional supermod-ular environment continues to robustly implement e-optimal outcomes in all close-by environments. Robust implementation of g-optimal outcomes is thus robust to small perturbations of the environment. This is in contrast to ex-post implementation which is not robust in this sense as only trivial social choice functions are ex-post implementable in generic environments.