The nationalization of party systems in 45 democracies (1975-2010)

Three main characteristics can be found in most of the Political Science comparative attempts regarding parties and party system nationalization. The far majority, in one hand, does not take account of countries beyond the Europeans or the USA and, in the other hand, many works do not care about the widely varying electoral weights between sub-national political levels within a given country. Additionally, few studies try to explain nationalization indexes beyond just using them to compare patterns: what are these indexes’ results related with? This paper aims to fill the first two gaps and to start affording the third. First of all, it includes among USA and main West European countries other Latin American, Asian and East European nations. In what refers to party nationalization, comparing 45 more heterogeneous democracies show interesting patterns and differences hidden by usual case selections that include just consolidated democracies. Secondly, this paper applies an index of nationalization developed by Daniel Bocshler that takes on account the weight of each region, district or sub-national. That index provides more reliable comparison across party systems, as it bases on the difference between the votes a party receive in a district and the votes it was expected to have there, given the weight of that district inside the country. Finally, results from that indicator are tested for correlation with other usual political variables such as the effective number of electoral parties, number of sub-national levels, system of government, Gini index of inequality of voters between sub-national levels within a given country, federalism, age of currently democracy. Preliminary conclusions suggest that the weighted index adopted modifies common understandings on several countries just by correctly considering regional differences of each one, and that some of the tested institutions help to explain variation on the degree of and party system nationalization.