Form of government, electoral system, and party system fragmentation: A global comparison

This study aims to determine the characteristics of party systems within the context of electoral systems, forms of government, and continents. There is no study in the literature that quantitatively reveals the relationship between the party system and forms of government. Furthermore, this study differs from other studies in that it deals with the relationship between the electoral system and the party system on a global scale. In the study, the effective number of parties (ENEP and ENPP) was calculated for the last three legislative elections of the countries governed by presidential, president–parliamentary, premier–presidential and parliamentary forms of government, using the Laakso–Taagepera Index. The dataset was then analyzed with ANOVA and post-hoc tests. The study revealed that party systems do not differ significantly from forms of government, that is, forms of government do not determine party systems. Similarly, party systems do not significantly differ in terms of the continents, that is, there are no continental party system characteristics of the forms of government. Also, the study confirmed that it is the electoral system that determines the party systems.