Party systems and executive accountability: The politics of investigative committees in Central and Eastern Europe

Abstract Parliaments are equipped with accountability mechanisms to uncover and sanction executive misconduct, yet the variation in their use across countries and over time remains poorly understood. This article links the frequency with which various constellations of MPs initiate ad hoc parliamentary investigative committees (ICs) to the institutionalization of party systems. It argues that the closure of the party system in the governmental arena, and particularly the degree of alternation in government, fosters the use of ICs due to the enhanced clarity of responsibility and competitive pressures. This argument is tested using a novel dataset of IC proposals in 97 cabinets across 10 countries of Central and Eastern Europe from the early 2000s to 2024. The findings indicate that under closed party systems, these accountability mechanisms are initiated more frequently both by opposition parties and a portion of coalition parties without the support of the remaining coalition partners. The article adds to the comparative understanding of parliamentary accountability as exercised by both opposition and government parties.