In a partnership game, each player's utility depends on the other players' actions through a commonly observed consequence (e.g. output, profit, price), which is itself a function of the players' actions and an exogenous stochastic environment. If a partnership game is repeated infinitely, and each player's payoff in the infinite game (supergame) is the long-run average of his expected one-period utilities, then efficient combinations of one-period actions can be sustained as Nash equilibria of the supergame even if the players cannot observe other players' actions or information, but can only observe the resulting consequences.

In this note we present an example of a repeated partnership game with imperfect monitoring in which all supergame equilibria with positive discount rates are bounded away from full efficiency uniformly in the discount rate, provided the latter is strictly positive. On the other hand, if the players do not discount the future, then every efficient one-period payoff vector that dominates the one-period equilibrium payoff vector can be attained by an equilibrium of the repeated game. Thus the correspondence that maps the players' discount rate into the corresponding set of repeated-game equilibrium payoff vectors is discontinuous at the point at which the discount rate is zero.