We provide a new proof of the non-emptiness of approximate cores of games with many players of a finite number of types. Earlier papers in the literature proceed by showing that, for games with many players, equal-treatment cores of their "balanced cover games", which are non-empty, can be...

This review discusses research demonstrating that club economies and coalition economies with many participants and relatively small effective groups (clubs, jurisdictions, or coalitions) are competitive. Small groups are effective if all or almost all gains to collective activities can be...