Factors of party system fragmentation: A cross-national study

This article uses a representative sample of elections held in 82 countries of the world (1993-2012) for a statistical analysis of factors that explain the number of parties in national legislative elections. The analysis confirms that the proliferation of candidates and/or parties at the district level contributes to the number of national parties, but the other crucial determinant is party system nationalisation. Several factors that are believed to have an impact on party system fragmentation, such as economic wealth, federalism, linguistic fractionalisation and population size, exert their influence on the number of national parties indirectly, by affecting either the number of district parties or party system nationalisation. At the same time, the significance of many other factors, especially those pertaining to electoral systems and the general political-institutional context, can be properly estimated only if the strongest determinants of system-level fragmentation are controlled for.