State enforcement of federal standards: Implications for interstate pollution

This paper explores the relationship between interstate air pollution and the division of power between federal and state agencies in setting and enforcing standards. In the context of the US Clean Air Act we argue that the EPA is able to monitor the adoption of technology-based standards more closely than it can monitor state-level enforcement, and that this causes an effective division of control between federal and state agencies. Our analysis offers three main insights into the interstate pollution problem in this setting. First, states have an incentive to enforce standards less stringently on firms located close to downwind borders, and this leads to excessive interstate pollution in equilibrium. Second, there can arise an inherent substitutability in the regulatory problem between strict standards and compliance effort, and this creates a strategic linkage between the federal policy on standards and state policies on enforcement. In particular, a tighter federal standard can induce less selective enforcement but can also lead to less enforcement overall. Third, states will attempt to neutralize the impact of location-based federal standards (that specifically target interstate pollution) in a way that actually exacerbates the underlying enforcement problem.