Party Instability in Parliaments

Elected representatives are widely expected to remain affiliated with the political parties that got them elected. However, party switching in parliaments is common, if not endemic, in many established and young democracies. By changing their affiliation, elected representatives create party instability: new parties form, existing parties dissolve, and the size of parties in parliament changes. Party instability may have important effects on election and government formation outcomes, public policy and voter representation. This project examines party instability in parliaments in European democracies. It has three objectives: to map out diverse forms of instability, to explain why instability occurs, and to understand whether and how instability affects voter support of parties. A key idea in the project is that party switching can happen in different ways. For example, elected representatives may act individually or in coordination with current co-partisans, legislators from other parties or independents; they can leave or be expelled from their current parties; and may enter existing parties, form new parties, or become independents. Clear definitions and careful analyses of different forms of instability will therefore constitute an important focus of the project. Moreover, the project will examine whether and how external shocks and events (for example, economic crises) lead to party instability. The project aims to provide detailed information about each instance of party switching in three North-Western European countries (Ireland, Norway and the Netherlands) since the 1960s and five countries in Central and Eastern and Southern Europe (Estonia, Italy, Lithuania, Poland and Romania) since the 1990s. The project will also establish the Observatory of Parliamentary Party Switches (OPPS) that records ongoing instability in the same set of eight countries as well as five additional Western European countries

Party instability is on the rise in democracies new and old. Mainly associated with the emergence of new parties, party instability is also prevalent in parliaments in a variety of forms. Parliamentary representatives, acting individually or in coordination with current co-partisans, legislators from other parties or independents, can enter existing parties, form new parties, or become independents without a formal party affiliation. Such parliamentary party instability can have important effects on electoral and government formation outcomes and stability of cleavage structures. Endemic instability can undermine government stability, policy representation, electoral accountability, control of corruption, and development of important public policies. However, party instability can also change stultified party systems in old democracies or hinder the formation of dominant party systems and democratic backsliding in young democracies. In this project an international research team examines parliamentary party instability in eight carefully selected established and young democracies over several last decades. First, we unravel the previously under-researched complexity of parliamentary party instability through careful conceptual work and the collection of extensive quantitative and rich qualitative data on each instance of legislative party switching in our country sample. Second, we develop empirically-driven theoretical arguments explaining these diverse forms of party instability as a result of external shocks and events, while accounting for the concerns of switcher politicians, their current parties, and potential receiving parties. We test these arguments by combining advanced quantitative analyses with qualitative and experimental approaches. Third, we investigate the impact of diverse forms of party instability on party popular support while considering carefully the two-way relationship between party instability and party support.