When and Why do Regional Organisations Mingle? Arrangements and Determinants of Interregional Cooperation

Many regional organizations (ROs) have developed formal relations with each other. This paper maps interregional cooperation of more than 50 ROs since the end of the WWII until today and answers the following research questions: How does the number of interregional agreements differ between ROs, geographical regions, policy areas and over time? When and under which conditions do ROs cooperate with each other? Drawing on rationalist and constructivist approaches on international and regional cooperation, the paper develops a set of competing hypotheses that specify under which conditions ROs start outreaching to each other and enter into formal agreements. The hypotheses are empirically examined with qualitative methods. The paper presents illustrative case studies by applying process-tracing techniques to ROs with large and small membership and which are economically rich or poor. Thereby, it sheds light on the conditions under which ROs become active and enter interregional relations.