A model of electoral competition between national and regional parties

We consider a one-dimensional model of electoral competition with national and regional parties. There are two regions and three parties—one national party and one regional party for each region. We divide the paper into two parts—homogeneous and heterogeneous regions. In the former, the policy positions of the national party and the regional party of the region with the greater number of constituencies coincide with the favorite policy position of the region-wide median voter. In the latter, the national party chooses a policy position in a maximal isolation set, while the two regional parties choose policies on the same side of the national party’s policy as their own respective region-wide medians. For a given outcome function, the national party performs better when the regions are heterogeneous. In the homogeneous regions case, the national party can at best do as well as the regional party of the region with the greater number of constituencies. Our results are broadly consistent with intuition and evidence