Mollifiers for games in normal form and the Harsanyi-Selten valuation function

The concepts of disruption and mollifiers ofCharnes/Rousseau/Seiford 1978] for games in characteristic function form are here extended to games in normal form. We show for a large class of games that theHarsanyi-Selten 1959] modification ofvon Neumann /Morgenstern's 1953] construction of a characteristic function for games in normal form, to take better account of “disruption” or “threat” possibilities, yields a constant mollifier. In general, it can be non-superadditive when the von Neumann-Morgenstern function is superadditive, and it also fails to take account of coalitional sizes. Our extended “homomollifier” concept does, and always yields a superadditive constant sum characteristic function.