"When consumers exhibit present bias and are time-inconsistent, the standard solution to market failures caused by externalities-Pigouvian pricing-is suboptimal. I investigate policies aimed at externalities for time-inconsistent consumers. Welfare-maximizing policy in this case includes an...

We explore the effects of environmental taxes that imprecisely target pollution. A review of actual policies indicates few (if any) examples of a true tax on pollution. More typically, environmental taxes target an input or output that is correlated with pollution. We construct a simple...