To Join or Not to Join, and Which One to Join: Overcoming Domestic Political Polarization and Constraints through IGO membership

Do domestic political constraints affect the decisions of leaders to join IGOs? Under what circumstances are political leaders more likely to join IGOs with a high degree of institutionalization (Boehmer et al. 2004) and what types of IGOs? Joining Intergovernmental Organizations (IGOs) could entail several steep costs. However, countries continue to join IGOs but also join IGOs with a high degree of institutionalization. The literature has explained this pattern by looking at the causes of IGO membership at the international level. However, the domestic causes of IGO membership have not been fully explored in a systematic manner. We argue that countries use IGOs as a tool through which they overcome political constraints at home and to lock in policy changes. By using an original and more complete data set (179 countries between 1975 and 2005) categorizing each IGO by their level of institutionalization and purpose, we find that countries do not simply join any organization indiscriminately: Leaders facing a high degree of political constraints are more likely to choose IGOs with a high level of institutionalization that enables them to push for and lock in policy changes. We also found the countries that experience high levels of democracy or regime durability are less likely to join interventionist organizations. While democratization is positively associated with positive changes on IGO membership, its effect is smaller compared to the effect of political constraints.