Impact of National Politics on Local Elections in Scandinavia

The impact of national politics on local county and municipal elections since about 1970 is studied at the aggregate national level in Denmark, Norway and Sweden. At this level, the local politics swing, i.e., the change in party support from one local election to the next, can to a high degree be predicted by the swing in national politics support. In Sweden, the national politics support is simply the party support at the national election held on the same day as the local elections, while opinion polls are used for Denmark and Norway. With the swing model for proportional impact from national to local politics, it appears that the national impact is stronger in Norway and Sweden than in Denmark. The swing model can be improved by including feedback from the difference between local politics and national politics support at the previous election. The feedback force from national to local politics estimated by the feedback model is also stronger in Norway and Sweden than in Denmark. Further, a preliminary analysis of Danish data indicates that the feedback model is especially relevant for analysis of data from the individual municipalities.