What drives scrutiny efforts in the European Parliament?

In recent decades, the European Parliament (EP), as an institution, and individual European legislators have increasingly assumed the role of scrutinizing and holding accountable other EU institutions and agencies (Ripoll Servent 2018; Font and Pérez Durán 2016). This includes not only post-legislative scrutiny of European policies, but also scrutiny of EU polity aspects. The paper disentangles the frequency of such efforts and analyses their institutional and individual level determinants drawing on almost 115,000 written questions submitted by MEPs between 2001 and 2018. We follow a text-as-data approach and perform an automated content analysis using a polity/ policies dictionary. Our negative binomial regression models indicate that the scrutiny of policy and polity issues by MEPs is driven by their status in the legislature's committees, the incentives created by the electoral systems under which they are elected, but also by the positions of their national parties on the EU integration dimension.