The number of naturalisations has increased significantly from the late 1970s, from about 2 000-3 000 naturalisations a year, to 41 000 naturalisations in 2021.

Different groups may have different motivations for applying for Norwegian citizenship. Norwegian citizenship entails both potential advantages and disadvantages, depending on one’s original citizenship. We see an indication of this in the composition of those obtaining Norwegian citizenship. The largest groups originate from countries outside the EU/EFTA area, particularly countries in Asia and Africa. Most numerous are persons with previous citizenships from Somalia, Iraq and Pakistan. Many of the immigrants who have received Norwegian citizenship have arrived as refugees or through family reunification to refugees. Some large groups of immigrants are underrepresented among the transitions, especially citizens from the Nordic countries and countries in the EU/EFTA-area. However, the number of transitions among persons from these countries has increased greatly since the abolition of the principle of one citizenship in 2020.

Slightly more women than men obtain Norwegian citizenship. While the women first and foremost have come to establish and reunite with family, the men have primarily arrived as refugees and for work. Most immigrants are young adults when they naturalise, while Norwegian-born to immigrant parents typically are very young. The period of residence for immigrants from countries in Asia and Africa and stateless persons is considerably shorter than for members of other country groups. Immigrants with previous citizenship from the USA, the Nordic countries and other EU/EFTA-countries are those with the longest residency among the naturalised.

An analysis of three cohorts of immigrants who arrived in the years 2006 to 2008 reveals great variation in the proportion with Norwegian citizenship during the first ten years of their stay. About eight out of ten of those arriving as refugees and family immigrants to refugees have Norwegian citizenship after ten years. There are particularly few transitions among labour migrants and family immigrants to labour migrants: only 5 and 16 per cent respectively. Most of the people who have come as stateless or with citizenship from countries such as Afghanistan, Iraq or Somalia have Norwegian citizenship. Very few Lithuanians, Germans and Poles are naturalised. Stateless persons furthermore tend to obtain Norwegian citizenship very early: more than half of them are Norwegian citizens after four years. Persons who have come to Norway as children tend to obtain citizenship earlier than those who have arrived as adults.

There also seems to be a relation between having Norwegian citizenship and emigration, especially among labour migrants and family immigrants to labour migrants. Immigrants who did not have Norwegian citizenship ten years after immigration were significantly more likely to have emigrated five years later. However, the relation between not being naturalised and emigrating appears to be less clear among refugees and their family immigrants.

The proportion of Norwegian citizens among immigrants resident in Norway as of 1.1.2022 largely reflects the patterns seen in the preceding chapters. Not surprisingly, many of the immigrants from countries from which there are many transitions tend to have Norwegian citizenship. These patterns are to a great extent also present among the descendants of immigrants. Very few Poles and Lithuanians born in Norway to immigrant parents have Norwegian citizenship. This is the case even among those who are old enough to have met the strictest requirements for residence time.