In spite of the formal responsibility for European Member states to ensure compliance, the EU´s decentralized policy implementation structure places subnational authorities (SNAs) in a rather important position to achieve compliance. Yet, few studies have gone beyond the national level when analyzing compliance to EU law. Parting from state-centric compliance research, this study investigates instances of subnational noncompliance to EU environmental law, giving agency to subnational levels. In order to explain why some SNAs violate EU law more than others, I argue that compliance to EU law is a multilevel phenomenon wherein SNAs play crucial roles in both the implementation and compliance of EU policy objectives. Building on insights from compliance theory, I test the extent to which politicization, capacity, and power condition the capacity and willingness of SNAs to deal with costs associated with complying to EU law. Instances of noncompliance are measured based on environmental infringements occurring between 2005 and 2020, uncovering notable variation from SNAs across Europe. In turn, opening the door to variation within and across countries helps traverse levels of analysis while adding to current understandings of compliance to European law.
