In this article, I present the second version of the Citizenship Regime Inclusiveness Index (CITRIX 2.0). It measures the inclusiveness of regulations for immigrants’ access to citizenship across 23 OECD countries from 1980 to 2019, zooming in on four essential policy components: conditions regarding (1) birthright; (2) residence; (3) renunciation; and (4) integration. While explaining the construction of the dataset, I advance a synthetic approach to index methodology. The main idea of this approach is to use statistical dimensionality tests to validate deductively specified additive concept structures. This is the first lesson we can learn from CITRIX. After validating the index in terms of content, dimensionality, and convergence, a short empirical analysis presents two additional lessons. First, after two cycles of liberalization and subsequent restrictive turns, mostly in integration conditions, aggregate citizenship policy inclusiveness has stagnated, but liberalized overall. 2003 marks the peak of liberalization. Second, there has been long-term convergence constituted by two phases of convergence with one diverging phase in between. I conclude that liberalization is more limited, and convergence more pronounced, than often assumed. CITRIX offers a versatile toolbox for future research to explore citizenship policies and their correlates. Regular updates are planned.

中文翻译：

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停滞的自由化、长期趋同和指数方法：来自 CITRIX 公民政策数据集的三个教训

在本文中，我介绍了公民制度包容性指数 (CITRIX 2.0) 的第二个版本。它衡量了 1980 年至 2019 年 23 个经合组织国家移民获得公民身份的法规的包容性，重点关注四个基本政策组成部分：（1）与生俱来的条件；(2) 居住地；(3) 放弃；(4) 整合。在解释数据集的构建时，我提出了一种索引方法的综合方法。这种方法的主要思想是使用统计维数测试来验证演绎指定的附加概念结构。这是我们可以从 CITRIX 学到的第一课。在内容、维度和收敛性方面验证该指数后，简短的实证分析提供了两个额外的经验教训。第一的，经过两个周期的自由化和随后的限制性转变，主要是在融合条件下，总体公民政策包容性停滞不前，但总体上是自由化的。2003年是自由化的高峰。二是长期趋同由两个趋同和一个发散相构成。我的结论是，自由化比通常假设的更加有限，趋同更加明显。CITRIX 为未来的研究提供了一个多功能工具箱，以探索公民政策及其相关性。计划定期更新。长期趋同由两个趋同阶段和中间一个发散阶段构成。我的结论是，自由化比通常假设的更加有限，趋同更加明显。CITRIX 为未来的研究提供了一个多功能工具箱，以探索公民政策及其相关性。计划定期更新。长期趋同由两个趋同阶段和中间一个发散阶段构成。我的结论是，自由化比通常假设的更加有限，趋同更加明显。CITRIX 为未来的研究提供了一个多功能工具箱，以探索公民政策及其相关性。计划定期更新。