While regime complexes, sets of overlapping institutions governing a common issue area, are frequently characterised by stable interinstitutional divisions of labour and incremental change, actor-centred approaches emphasise potentially disruptive cross-institutional strategies. I propose a conceptual framework highlighting the constraints under which states operate within regime complexes, focusing on the role of critical actors that cannot effectively be excluded from cooperation because of their contributions to international public goods and/or negative externalities that their non-participation would generate for cooperating states. Where such actors pursue conservative policy objectives, reformist actors have limited scope for employing cross-institutional strategies and cooperating through alternative club settings. This leads to incremental institutional change as those latter actors attempt to elaborate and develop pre-existing rules instead of creating new ones. I demonstrate the explanatory power of this approach for the formation of three Access and Benefit-sharing regimes within the Genetic Resources regime complex.

中文翻译：

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制度复合体、关键参与者和制度分层

虽然政权复合体，即管理共同问题领域的一组重叠机构，通常以稳定的机构间分工和渐进式变化为特征，但以行动者为中心的方法强调潜在的破坏性跨机构战略。我提出了一个概念框架，强调国家在政权复合体中运作的约束条件，重点关注关键行为者的作用，这些行为者不能有效地排除在合作之外，因为他们对国际公共产品的贡献和/或他们的不参与会产生负面外部性对于合作国。在这些行为者追求保守政策目标的情况下，改革派行为者采用跨机构战略和通过替代俱乐部环境进行合作的空间有限。这会导致渐进的制度变革，因为后者试图制定和发展预先存在的规则，而不是创造新的规则。我展示了这种方法对在遗传资源制度复合体内形成三个获取和利益分享制度的解释力。