In Morris, Oyama, and Takahashi (2023), we proposed and studied the notion of strict robustness, a strict version of robustness of Kajii and Morris (1997). This note discusses another strict version that had been introduced earlier by Oury and Tercieux (2007). By definition it is weaker than ours, and the two versions are equivalent in binary-action supermodular games. In many-action supermodular games, they are equivalent if the perturbations of the respective versions are restricted to be supermodular. Journal of Economic Literature Classification Numbers: C72, D82.

Key Words: Incomplete information, robustness, supermodular game, information design.

This version: April 21, 2025. PDF file