The Party Politics of Political Decentralization

In this dissertation, I ask why certain types of parties would agree to support creating or empowering sub-national governments. In particular, I focus on nationalized parties -- those that gain support from throughout a country. Political decentralization can negatively impact nationalized parties in at least two ways. First, it reduces the amount of power a party can enjoy should it win control of the national-level government. Second, previous studies show that political decentralization can increase party denationalization, meaning regional parties gain more support, even during national-level elections. I argue that nationalized parties may support decentralization when doing so reduces the ideological conflicts over national-level policy among voters whose support they seek. By altering political institutions, a party may be able to accommodate differing policy preferences in different parts of the country, or limit the damage to the party's electoral fortunes such differences could create.I primarily focus on the case of Scottish devolution in the United Kingdom, tracing the evolution of the British Labour Party's attitudes towards the issue. I argue that devolution became an integral part of the New Labour platform because it allowed the party to moderateits economic policies to cater to English preferences without losing Scottish votes to the Scottish National Party. I then develop a formal model representing the challenges a nationalized party faces when trying to win votes in more than one region of a country. I show that a party may be able to win votes using a combination of policy and political decentralization when it would be unable to do so using a single national-level policy alone. Furthermore, I hypothesize that a nationalized party should be more likely to support political decentralization when the preferences of voters in different regions diverge from each other. After applying this model to the United Kingdom, I explore some if its implications using the cases of decentralization in Spain and Belgium