Subnational research in comparative politics has been growing steadily in the last two decades. However, methodological advances have been rather limited. This article builds upon Snyder’s (Stud Comp Int Dev 36(1):93–110, 2001) subnational comparative method and extends its logic to the comparison of subnational units from different countries. It proposes a novel typology of multilevel research designs that focuses particularly on cross-national small-N analysis (CSNA). This research design offers three different logics of qualitative case selection to achieve a sound trade-off between internal and external validity. This article analyzes the advantages and limitations of the underlying logics of CSNA and illustrates their use with recent empirical research from Latin American countries. It concludes by highlighting its versatility and offers a series of best practices in order to produce more generalizable findings than the majority of single-country subnational comparisons.

中文翻译：

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多层次研究设计：案例选择、分析层次和范围条件

在过去的二十年里，比较政治的地方研究一直在稳步增长。然而，方法上的进步相当有限。本文建立在 Snyder (Stud Comp Int Dev 36(1):93–110, 2001) 地方比较方法的基础上，并将其逻辑扩展到来自不同国家的地方单位的比较。它提出了一种新的多层次研究设计类型，特别侧重于跨国小 N 分析 (CSNA)。该研究设计提供了三种不同的定性案例选择逻辑，以实现内部效度和外部效度之间的良好平衡。本文分析了 CSNA 底层逻辑的优点和局限性，并通过最近来自拉丁美洲国家的实证研究来说明它们的使用。