I study the optimal design of marketable permit systems to regulate various pollutants (e.g., air pollution in urban areas) when the regulator lives in a real world of imperfect information and incomplete enforcement. I show that the regulator should hale pollution markets integrated through...

I study the advantages of pollution permit markets over uniform emission (or technology) standards when the regulator has incomplete information on firms' emissions and costs of production and abatement (e.g., air pollution in large cities). Because the regulator observes only each firm's...