Quasiseparable aggregation in games with common local utilities

Strategic games are considered where each player's total utility is an aggregate of local utilities obtained from the use of certain "facilities." All players using a facility obtain the same utility therefrom, which may depend on the identities of users and on their behavior. Individual improvements in such a game are acyclic if a "trimness" condition is satisfied by every facility and all aggregation rules are consistent with a separable ordering. Those conditions are satisfied, for instance, by bottleneck congestion games with an infinite set of facilities. Under appropriate additional assumptions, the existence of a Nash equilibrium is established.