Citizenship Regime Inclusiveness Index Version 2.0 (CITRIX 2.0)

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.

本文推出公民身份制度包容性指数第二版（Citizenship Regime Inclusiveness Index，简称CITRIX 2.0）。该指数覆盖1980至2019年间的23个经济合作与发展组织（Organisation for Economic Co-operation and Development，简称OECD）成员国，用以衡量移民获取公民身份相关法规的包容性程度，并重点考察四大核心政策维度：（1）出生地原则相关条件；（2）居住要求相关条件；（3）放弃国籍相关条件；（4）融合要求相关条件。在阐释本数据集构建逻辑的同时，本文提出了一种适用于指数构建方法论的综合研究路径，其核心思路为通过统计维度检验，对演绎设定的加法式概念结构进行有效性验证——这亦是CITRIX 2.0带给学界的首要启示。在从内容效度、维度结构与趋同特征三个维度完成指数有效性验证后，本文通过一项简短的实证分析补充了两项额外启示：其一，尽管经历两轮自由化与后续政策收紧周期（其中多数收紧举措集中于融合要求领域），整体公民身份政策的包容性虽呈现停滞态势，但整体仍处于自由化进程之中，2003年为自由化程度的峰值年份；其二，长期来看，成员国间的公民政策包容性呈现趋同态势，这一过程包含两个趋同阶段，其间存在一段短暂的分化阶段。本文最终得出结论：相较于既有研究的普遍认知，公民身份政策的自由化进程更为有限，而成员国间的政策趋同特征则更为显著。CITRIX 2.0为未来探索公民身份政策及其关联因素的研究提供了一套通用化研究工具包，后续将定期进行数据更新。