We consider a single object allocation problem with multidimensional signals and interdependent valuations. When agents' signals are statistically independent, Jehiel and Moldovanu [Efficient design with interdependent valuations, Econometrica, 69(5):1237-1259, 2001] show that efficient and...

This paper studies when the presence of a small degree of ambiguity guarantees efficient implementation in general mechanism design settings. First, we show that if approximately efficient allocations are implementable in a Bayesian environment, then exactly efficient allocations are...