Discretionary Exemptions from Environmental Regulation: Flexibility for Good or for Ill

Many environmental regulations impose limits on harmful activities but include discretionary “safety valve” provisions allowing the regulator to grant exemptions that provide relief to regulated parties. We construct a theoretical model and explore cases in which this discretion serves good or ill. We show that when a regulation is otherwise inflexible, exemptions can improve social welfare, and perhaps reduce pollution, by distributing abatement more cost-effectively across polluters. However, these beneficial predictions rely on an unconstrained, fully informed, and benevolent regulator. In other cases, exemptions may not offer such gains; further, the discretionary nature of exemptions allows them to be abused.