The scope of anonymous voluntary bargaining under asymmetric information

We present a model of anonymous collective bargaining where individuals' pr eferences and information may be significantly interdependent. We show that the bargaining outcome becomes independent of individuals' preferences and information as the bargaining group increases in size; As a corollary, we show that anonymous voluntary bargaining completely fails in large groups. Either the difference between the bargaining outcome and the status quo van ishes as the size of the group becomes larger, or, the bargaining becomes c oercive and results in a violation of at least some individuals' rights. Th e result provides a rationale for the inherent difficulty of reform in the presence of asymmetric information.