We study ex post implementation in collective decision problems where monetary transfers cannot be used. We find that deterministic ex post implementation is impossible if the underlying environment is neither almost an environment with private values nor almost one with common values. Thus,...

We study ex post implementation in collective decision problems where monetary transfers cannot be used. We find that deterministic ex post implementation is impossible if the underlying environment is neither almost an environment with private values nor almost one with common values. Thus,...

We study the aggregate economic effects of diversity policies such as affirmative action in college admission. If agents are constrained in the side payments they can make, the free market allocation displays excessive segregation relative to the first-best. Affirmative action policies can...