What Makes MEPs Respond?: A Correspondence Field Experimental Approach to Study the Politicization of Democratic Backsliding in the European Parliament

How does public attention shape political responsiveness in the European Parliament? This study examines whether Members of the European Parliament (MEPs) are more likely to engage with external requests when these offer potential public visibility, and whether responsiveness varies across policy topics with different levels of political salience. A correspondence study field experiment targeting all MEPs is employed. In a two-wave design, each MEP is contacted twice with randomized combinations of sender and topic. Queries are framed either as requests for input for a cross-national journalistic article in which respondents may be named and quoted (treatment) or as requests for an anonymized academic research project (control). Independently, the topic of the query varies between democratic backsliding and EU Rule of Law conditionality (politically salient) and EU public procurement transparency (less politically charged). The design enables estimation of the causal effects of public visibility and issue salience on elite responsiveness, as well as their interaction. The study tests whether MEPs systematically reward media exposure with higher engagement and whether backsliding-related queries elicit greater responsiveness than technical transparency requests. Differential responsiveness to publicity is interpreted as evidence of the politicization of EP work and heightened incentives for public attention in representative behavior.