Democratic accountability requires that citizens can assign responsibility for policy outcomes, yet multilevel structures of government complicate this task as they blur lines of accountability and leave voters uncertain about which level of government is responsible. This study examines the extent to which Europeans are able to navigate the complex and ever-changing divisions of responsibility between their national governments and the European Union (EU). Specifically, we compare citizen and expert responsibility attributions to evaluate if and how voters can competently assign policy responsibility to the European Union. Using multilevel modeling to analyze survey and media data from 27 EU member states, we demonstrate that extreme attitudes decrease citizen competence by motivating biased information processing. Yet at the contextual level, highly politicized environments result in more correct allocations of responsibility by creating an information-rich context. Keywords: multilevel governance, attribution, responsibility, polarization, knowledge, European Union 1 Lack of political knowledge among citizens is well-documented (see e.g. Converse 1964; Delli Carpini and Keeter 1996). Indeed, the level of citizen ignorance about politics have led some scholars to suggest that "the low level of political knowledge and the absence of ideological reasoning have lent credence to the charge that popular control of the government is illusory" (Iyengar 1987, 816). Citizens living in systems of multi-level governance, such as the European Union (EU), face a greater challenge when it comes to holding their representatives to account, since they have the additional task of differentiating between multiple levels of government when deciding whom to credit and blame for policy outcomes (Arceneaux 2006;Cutler 2004 Cutler , 2008 de Vries et al. 2011;Johns 2011). Yet, if popular control is to be more than an illusion, then it is crucial that citizens have at least a basic understanding of the different levels of government responsibility and are able to assess their government's performance. The very notion of elections as a means of holding governments to account assumes that citizens are able assign responsibility for policy outcomes (Key 1966; Fiorina 1981;Rudolph 2003). Since attribution of responsibility is not a matter of preferences or policy positions, citizens cannot easily rely on proxies or shortcuts to help them distinguish governmental responsibility (Lupia 1994;Sniderman 2000). This raises the question of whether citizens are able to correctly differentiate responsibility between levels of national and supranational government. More fundamentally, it begs the question of what factors enable citizens to acquire the information necessary to do so. This article examines individuals' ability to attribute policy responsibility to the European Union. To be able to assess the degree of competence in citizens' responsibility judgments, we compare citizen evaluations to expert judgments. The theoretical fra...