Measuring intra-party democracy on a global scale

This research note presents two measures of intra-party democracy (IPD) used on a global scale. We distinguish between assembly-based and plebiscitary IPD which represent two distinct logics of intra-party decision-making. The instrument was developed in the context of the first round of the Political Party Database Project (PPDB) covering 146 parties in 25 countries. It is now applied for the first time to parties in countries on all continents. We cover 274 parties from the second round of the PPDB in 51 countries, which provides us with a unique opportunity to assess the applicability and validity of this measure and compare it over time. Our results show that the expected stability of IPD values go together with plausible change over time. This opens up the potential to trace changes of IPD in detail and to investigate possible reasons for these changes. Furthermore, the new data are ideally suited to be applied in different institutional and cultural contexts.