“…In bold strokes, two types of methods have proved to be powerful in identifying equilibria that are robust in various aspects: namely, the potential method (due to Monderer and Shapley (1996); see also Blume (1993), Sorger (1999, 2002), Ui (2001)) and the risk-dominance method (due to Harsanyi and Selten (1988); see also Kandori, Mailath, and Rob (1993), Young (1993), Matsui and Matsuyama (1995), Morris, Rob, and Shin (1995), and Kajii and Morris (1997)). These criteria, however, are very demanding and such concepts fail to exist in many games.…”