T H E G L O B A L S TAT E O F C I T I Z E N S H I P That said, the legal requirements tell only one half of the story. Worldwide, over 90% of all ordinary naturalisation procedures are discretionary, meaning that applicants who meet all the legal requirements can still be rejected on various grounds. Only around 20 countries provide an entitlement to ordinary naturalisation in their laws. Research from Europe finds that applicants face not only significant discretion, but also significant documentation, bureaucracy and costs, all with limited state support, public information and judicial review. Implementation is likely an even more important issue in lower-income or autocratic countries, with greater gaps in the rule of law. Bringing it all together Overall, ordinary naturalisation policies are one of—if not the strongest—factors shaping ordinary immigrants’ opportunity and propensity to become citizens of their new country, according to the many international studies linking naturalisation rates with policies. To illustrate this relationship, we aggregate the indicators discussed above into an index of citizenship law inclusiveness (using the aggregation formula developed by Samuel D. Schmid, with higher scores indicating more inclusive laws) and compare the scores on this index with citizenship acquisition rates among high-income OECD destination countries. The positive correlation between the inclusiveness of citizenship laws and acquisition rates indicates that, indeed, immigrants are more likely to acquire the citizenship of their country of residence under more facilitated institutional conditions. The association is moderately strong (r = 0.39) as, on average, countries need to move up 25 points on the 100-point inclusiveness scale to achieve an increase of one percentage point in immigrants’ naturalisation rates. The correlation cannot be perfect as naturalisation rates are also influenced by demographic factors, such as the number of recent immigrants who do not yet meet residence requirements, and origin country factors, including the level of development and citizenship policies of these states. 3.5 CITIZENSHIP ACQUISITION RATES BY REGIME INCLUSIVENESS Each dot represents a score for citizenship acquisition rates and regime inclusiveness of a countr y in a year Naturalisation rate (%) 9 Significant and moderately strong positive association | r = 0.39 (p <0.001) 6 3 0 20 40 Citizenship regime inclusiveness index Source: GLOBALCIT Citizenship Law Dataset, v3, modes: A06_yrs, A06b-A06f 24 60 80