Power versus Ideology: Political Group Switching in the European Parliament

Abstract

Why do legislators switch party? We seek to identify whether “party switching” is mainly determined by power (to join a more influential party) or ideology (to join a party with closer policy goals). We focus on the 557 cases of political group switching in the European Parliament between 1979 and 2014. We find that most of these cases were from smaller, more marginal, and oppositional groups, to larger, more pivotal, and governing groups. Nevertheless, we also find that ideological congruence (between an MEP and his or her prospective group) was an important determinant of political group switching.

Delegation of committee reports in the European Parliament

“…Many MEPs switch party or political group affiliations (Hix and Noury, 2018). To account for the possibility that political group switchers were rewarded by their new groups through report allocation, we include a dummy-variable for party switchers.…”

Party group collapse and strategic switching in the European Parliament

“…Consequently, the ‘power’ associated with seat share and access to offices should function consistently for both groups and delegations. Despite this, the literature determines that MEPs from the largest groups have significantly lower odds of switching, while members from the most powerful delegations have significantly increased odds of changing labels (Hix and Noury, 2018: 567). If weakly institutionalized groups are both more likely to disintegrate, and more likely to have dominant delegations, then this may explain why larger NPDs have higher odds of switching in models which do not control for group collapse.…”

“…Hix and Noury (2018) theorize that politicians’ desire for ‘power’ and concern with ‘ideology’ drives switching behavior. In the EP, ‘power is allocated between the national delegations in a broadly proportional way, which means that the larger national delegations are able to obtain the key committee positions and rapporteurships won by a group’ (Hix and Noury, 2018: 559); therefore, office-seeking members from bigger EPGs and NPDs should be less likely to leave organizations with greater access to leadership posts. Consequently, the ‘power’ associated with seat share and access to offices should function consistently for both groups and delegations.…”

“…The party switching literature focuses primarily on goal-oriented parliamentarians, like Karim, who swap party labels in order to gain political benefits (Heller and Mershon, 2009). This perspective is also dominant in studies of EP party group switching, where the unit of analysis is either individuals or national party delegations (NPDs), and switchers pursue either ‘power’ or ‘ideology’ (Hix and Noury, 2018). In the EP, however, party group collapse, as observed in the TDI and ITS cases, explains an extraordinary number of switches.…”

“…Over 10% of members changed group labels during the first seven EP terms (Hix and Noury, 2018: 558), which makes this an interesting case because, when compared to national parliaments, only Brazil and Italy have consistently higher frequencies of switching (Heller and Mershon, 2005; O’Brien and Shomer, 2013). This article contributes to our understanding of this phenomenon by identifying party group collapse as the direct cause of the majority of switchers during the period of 1979–2009.…”