Adaptation and Institutionalization: Political Parties' Response to External Shocks

The study presented in this paper aims to show that political parties—either an individual party or parties as a whole—respond to external shocks, such as rising electoral volatility, by adjusting their level of organizational institutionalization. Previous studies often presume institutionalization of party organizations to be the cause of institutionalization of party systems. In this study, we reverse the causal relationship to propose an alternative view: parties institutionalize by adapting themselves to party system change. By utilizing the Political Party Database (PPDB), we constructed indexes to measure the institutionalization of party organizations and to explore how they are affected by de-institutionalization of the party system. In doing so, we emphasize party adaptability in uncertain environments.