„In almost all countries (except Austria, Estonia and Greece), immigrants who have lived in the host country for more than five years are more proficient in literacy than those who have recently arrived. The difference between the two groups is particularly marked in the Nordic countries, where many immigrants need time to acquire language skills, and where comprehensive integration policies will have helped immigrants who have stayed in the country for longer to overcome any initial difficulties.“
OECD (Hrsg.), „Why are immigrants less proficient in literacy than native-born adults?“ (2017), S. 3