How cohesive is the kingmaker of the European Parliament? A roll call-vote study of voting cohesion in the Liberal Party Group of the European Parliament in EP8 and EP9

Abstract: Voting cohesion in the European Parliament is a thoroughly studied field, however a deep dive into the kingmaker of coalition building, the liberal party group, has yet to be done. This thesis attempts to illustrate how voting cohesion varies within the Alliance of Liberals & Democrats and Renew Europe respectively, and what factors can explain variation in cohesion. Specifically, how cohesion varies across policy area, how ideological heterogeneity affects cohesion and the differences in cohesion between ALDE and Renew. Two theories were used: the two principal-dilemma and the issue of salience, which hypothesizes that defection in voting will occur when differences in opinions (heterogeneity) is present, and that the influence of the European party group has decreased in favor of the national party discipline. The study was conducted using roll call-votes from 2014 to 2022 in the European Parliament, and ideological positionings from Chapel Hill expert surveys. To calculate the result a cohesion index and standard deviations were used. The results show that cohesion varies across policy areas and that there is a weak relationship between heterogeneity and low cohesion, and that the shift in policy and power that occurred with the creation of Renew has influenced cohesion. Furthermore, there is support for the two principal-dilemma that MEPs are controlled by EPG and national party discipline.