A 2021 study by Baten and Llorca-Jaña shows that regions with a relatively high share of North European migrants developed faster in terms of numeracy, even if the overall number of migrants was small. This effect might be related to externalities: the surrounding population adopted a similar behavior as the small non-European immigrant group, and new schools were created. Ironically, there might have been positive spillover effects from the educational investment made by migrants, at the same time numeracy might have been reduced by the greater inequality in these regions. However, the positive effects of immigration were apparently stronger.