Does capacity increase compliance? Examining evidence from European cooperation against air pollution

Scholars commonly hypothesize that enhanced capacity—improved ability to do as agreed—increases states’ compliance with international agreements. In contrast, using a novel dataset that covers 31 states and three decades of cooperation, I find a negative effect of capacity on compliance. To help explain this seemingly counterintuitive finding, I offer a novel conjecture of the capacity–compliance relationship. In particular, I argue that the effect of capacity may vary substantially across states, because states’ intention to comply constitutes a crucial intervening variable. Among reluctant states pursuing policy goals that affect compliance negatively, high capacity may in fact cause noncompliance. I exemplify the conjecture through evidence from a high-capacity noncompliant state (Norway).