The principal way in which formal citizenship status is acquired is on the basis of birth, whether by descent (ius sanguinis) or territory of birth (ius soli), and most people retain their citizenship of birth for life. Yet birthright citizenship laws have received less attention than naturalisation procedures. Drawing on GLOBALCIT data on citizenship laws in 177 countries in 2016, and indicators of birthright citizenship laws constructed from these, we analyse how global provisions for birthright citizenship vary across the world. We examine the extent to which provision is automatic and unconditional or subject to conditions or restrictions, and the implications for inclusion, in particular of immigrants. Almost all states provide for ius sanguinis citizenship, although with varying restrictions, especially for those born to citizens abroad. Ius soli is unconditional in a small minority of countries, but in half the countries studied it is limited to foundlings and children who would otherwise be stateless, and it is entirely absent in some. Different levels of conditionality of ius soli citizenship exclude the children of immigrants from citizenship of the country in which they live, and can also produce statelessness. Notwithstanding international laws and conventions, some birthright provisions also explicitly exclude on the basis of the marital status of parents, and on gender, racial, ethnic, religious or cultural grounds—all with potentially significant impact on immigrants. Finally, birthright citizenship laws display clearly differentiated geographical patterns, and ius soli is by no means always strongly provided in countries with the largest immigrant populations.

中文翻译：

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全球出生公民权法：如何包容？

获得正式公民身份的主要方式是基于出生，无论是血统 (ius sanguinis) 还是出生领土 (ius soli)，大多数人终生保留其出生公民身份。然而，与入籍程序相比，出生公民权法受到的关注较少。利用 GLOBALCIT 2016 年 177 个国家/地区的公民法数据，以及由此构建的出生公民权法律指标，我们分析了全球出生公民权规定在世界范围内的差异。我们研究了提供是自动和无条件的或受条件或限制的程度，以及对包容的影响，特别是对移民的影响。几乎所有州都提供血统主义公民身份，尽管有不同的限制，特别是对于那些出生在国外的公民。Ius soli 在少数国家是无条件的，但在研究的国家中，有一半仅限于弃儿和儿童，否则他们将成为无国籍人士，而在一些国家中则完全没有。ius soli 公民身份的不同程度的条件将移民的子女排除在他们居住的国家的公民身份之外，也可能导致无国籍状态。尽管有国际法和公约，一些与生俱来的条款也根据父母的婚姻状况以及性别、种族、民族、宗教或文化原因明确排除在外——所有这些都可能对移民产生重大影响。最后，与生俱来的公民权法显示出明显不同的地理模式，移民人口最多的国家并不总是严格规定 ius soli。