Public Bads, Heterogeneous Beliefs, and the Value of Information

This paper develops a simple model of public bads where players have heterogeneous beliefs about the consequence of their collective action. Properties of equilibrium and its relation to beliefs and preference are examined, followed by a detailed investigation of the impacts of new information. Our analysis sheds light on an important trade-off associated with information policies in the presence of belief heterogeneity and ambiguity. In particular, we show that newly available information can unambiguously worsen the free-riding problem even when it better reflects the correct risk than the players’ beliefs. Adding information noise will never mitigate the public-bad nature of the problem if players are equally confident about their beliefs. When the beliefs are highly heterogeneous, however, a certain amount of information noise can be Pareto-improving, for which the degrees of risk and ambiguity aversion play asymmetric roles.