City networks (CNs) are often enthusiastically regarded as key actors in processes of Europeanization and multi-level governance (MLG) policy-making in Europe and beyond. However, systematic research on highly contentious issues like migration is still scarce. Building on an understanding of MLG as a specific mode or instance of policy-making, in this article I seek to understand why and how CNs engage in MLG-like policy-making on a typical issue of state sovereignty. I apply the causal process-tracing method to analyse the genesis and policy actions undertaken in the last two decades by two migration CNs in different multi-level political settings: the Eurocities Working Group on Migration and Integration (WGM&I) in the EU and Welcoming America (WA) in the US. The results show that, notwithstanding the differences in the institutional settings, in both contexts instances of MLG policy-making have taken place in the shadow of the will of the national governments, which remain fundamental gate-keepers even in the EU supranational polity, where the European Commission has been particularly active in supporting migration CNs' initiatives.

中文翻译：

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通过多层次治理来治理移民？欧美城市网络*

城市网络 (CN) 通常被热情地视为欧洲及其他地区欧洲化和多层次治理 (MLG) 政策制定过程中的关键参与者。然而，对移民等极具争议性问题的系统研究仍然很少。基于将 MLG 作为一种特定的政策制定模式或实例的理解，在本文中，我试图了解 CNs 为何以及如何在国家主权的典型问题上参与类似 MLG 的政策制定。我应用因果过程追踪方法来分析过去二十年来两个移民 CNs 在不同的多层次政治环境中采取的起源和政策行动：欧盟的欧洲城市移民和融合工作组 (WGM&I) 和欢迎美国(WA) 在美国。结果表明，