The link between security and economic exchange is widely recognized. But when and how much do geopolitical interests matter for economic cooperation? While existing work focuses on bilateral trade and aid, we examine how geopolitics shapes membership in multilateral economic organizations. We demonstrate that substantial discrimination occurs as states welcome or exclude states based on foreign policy similarity. Biased selection of members can politicize economic cooperation despite multilateral norms of non-discrimination. We test the geopolitical origins of institutional membership by analyzing new data on membership patterns for 231 economic organizations from 1949 – 2014. Evidence shows that security ties shape which states join and remain in organizations at both the formation and enlargement stages. We use a finite mixture model to compare the relative power of economic and geopolitical considerations, finding that geopolitical alignment accounts for nearly half of the membership decisions in economic institutions.

安全与经济交流之间的联系已得到广泛认可。但是，地缘政治利益对经济合作何时何地重要？尽管现有工作集中在双边贸易和援助上，但我们研究了地缘政治如何影响多边经济组织的成员资格。我们证明，当国家欢迎或排斥基于外交政策相似性的国家时，就会发生实质性歧视。尽管存在多边非歧视性准则，但成员的有选择的偏见仍可能使经济合作政治化。我们通过分析1949年至2014年间231个经济组织的成员资格模式的新数据，来检验机构成员资格的地缘政治渊源。证据表明，安全关系决定了国家在组织形成和扩大阶段都加入并保留在组织中。经济机构中一半的成员资格决定。