The international state system, like all social systems, is permeated by hierarchical relationships sorting societal members into systems of institutionalized inequality. Recent scholarship has produced an impressive record of the varieties, mechanisms and outcomes of inequality production in international society. Less understood is how hierarchies inside intergovernmental organizations (IGO) become institutionalized, how and why they might change or even collapse. Drawing on recent stratification research in global governance, this article shows how institutionalized inequality through systems of tiered membership can be a highly instable mechanism of hierarchy production under constant pressure for adaptation and de-hierarchization from below. I use the example of a multi-layered system of membership stratification as it emerged over time in the European Organization for Nuclear Research (CERN) to demonstrate how agency restraint and system rigidity designed into institutional systems of IGO membership can emerge as central drivers for stratification to go awry.

国际国家体系与所有社会体系一样，渗透着等级关系，将社会成员分类为制度化的不平等体系。最近的学术研究对国际社会不平等产生的种类、机制和结果产生了令人印象深刻的记录。鲜为人知的是政府间组织 (IGO) 内部的等级制度是如何制度化的，它们如何以及为什么会发生变化甚至崩溃。借鉴最近全球治理的分层研究，本文展示了在来自下层的适应和去等级化的持续压力下，通过分层成员制度制度化的不平等如何成为一种高度不稳定的等级制度生产机制。