Experts and the general public often perceive environmental problems differently. Moreover, regulatory responses to environmental issues often do not coincide with consensus expert recommendations. These two facts are mutually consistent—it is unlikely that regulations based on factual claims that are substantially different from voters’ opinions would be politically feasible. Given that the public’s beliefs constrain policy choices, it is vital to understand how beliefs are formed, whether they will be biased, and how the inevitable heterogeneity in people’s beliefs filters through the political system to affect policy. We review recent theoretical and empirical work on individual inference, social learning, and the supply of information by the media and identify the potential for biased beliefs to arise. We then examine the interaction between beliefs and politics: can national elections and legislative votes be expected to result in unbiased collective decisions, do heterogeneous beliefs induce strategic political actors to alter their policy choices, and how do experts and lobby groups affect the information available to policymakers? We conclude by suggesting that the relationship between beliefs and policy choices is a relatively neglected aspect of the theory of environmental regulation, and a fruitful area for further research.