Size and party system fragmentation

The present study tests the assumption that size affects party system fragm entation. Three dependent variables are used: the number of parties, the el ectoral support for the leading party, and the effective number of parties. The study operates on two levels. On the macro level, the research populat ion consists of 77 countries with free party systems. On the micro level, l ocal units in Great Britain and Finland constitute the object of research. The impact of the following intervening variables is controlled for: the ef fective threshold, presidentialism, socioeconomic diversification, and ethn ic and religious diversity. On the macro level, the results show that size contains far more explanatory power than any other variable. This holds tru e for countries using a plurality electoral system as well as those using a proportional electoral system. On the micro level, there is a strong assoc iation between the size of the population and the number of parties, wherea s the other dependent variables are insensitive to variations in size.