Electoral Reform and Party System Change: An Analysis of Nordic Elections with Two Different Electoral Systems

Electoral system reforms are frequently discussed in various parts of the world, although major electoral system changes have been quite rare in established democracies. This article aims at predicting how the party systems in Denmark, Finland, Norway and Sweden would change if elections were conducted under a plurality system or a mixed‐member majoritarian system. To this end, results of the last parliamentary elections are recalculated. The analyses show that the Nordic party systems would be subjected to drastic change. In Denmark, plurality elections would create a two‐party system; in Finland, Norway and Sweden, one party would be much larger than the others. Keskusta and Arbeiderpartiet would be superior to the other parties in Finland and Norway, respectively, whereas Socialdemokratiska Arbetarepartiet would almost take complete control over the Swedish legislature. In practice, smaller parties would have to team up with larger ideologically similar parties. Under a mixed electoral system, several small and medium‐sized parties would survive, but in most countries, the main competition would take place between two basic political alternatives. Smaller parties are well‐advised to go against electoral system reforms that involve single‐member districts.