Regulating Global Externalities

The question in which we are interested is how a market inhabited by multiple agents, about whom we are differentially uncertain, and who trade goods the use of which imposes a negative effect on others, is to be ideally regulated. We show that a priori asymmetric uncertainty, when combined with a posteriori observed outcomes, is a rich source of information that can be used to reduce aggregate uncertainty. The observation implies that whereas asymmetric information usually entails a cost on welfare, it can help achieve greater efficiency in regulation.