“…See, for example Bolger (1986), Fishburn (1973), Rubenstein (1980). More recently, there has been considerable attention (in, for example, Amer et al, 1998;Bilbao, 2000, Bilbao et al, 2008a, 2008bBolger, 1993Bolger, , 2000Machover, 1997, 1998;Freixas, 2005aFreixas, , 2005bLindner, 2005;Tchantcho et al, 2008) paid to the question of how to modify various power indices so as to take account of abstention. In Freixas and Zwicker (2003), we introduce a class of structures -the ( j,k) simple games, or ( j,k) games, for shortthat generalize simple games by allowing j ordered levels of approval in the input and k ordered levels in the output.…”