Robust competitive auctions

•The Revelation Principle is not readily applicable in markets with many principals.•Does a seller want to deviate to any mechanism in competing auctions (Peters 1997)?•The sufficient condition for the robustness is embedded in its notion of equilibrium.

A competitive distribution of auctions (Peters 1997) is robust to the possibility of a seller's deviation to any arbitrary mechanisms, let alone direct mechanisms because the sufficient condition for the robustness is embedded in its notion of equilibrium.