I analyze a principal-multiple agent model in which agents have imperfect informa-tion about their abilities. When performance is affected by shocks that are common to everyone (such as task difficulty), performance comparisons with others are useful in forming beliefs about own ability. Beliefs, in turn, affect effort and hence subsequent performance. In this context, I explore the principal’s organizational design prob-lem where the amount of interim information disclosed to agents about each other’s performances is a choice variable. I find that the optimal disclosure policy depends on: (1) the degree of substitutability of the agents ’ performances in the principal’s payoff function; and (2) the amount of discretion the principal has ov...