Andersson specialized in toponymy. He was the publisher of Namn och bygd and co-publisher of Studia Anthroponymica Scandinavica. He was the author of a large number of books and articles on Swedish place names and personal names. Andersson was a member of the Royal Society of the Humanities at Uppsala, the Royal Gustavus Adolphus Academy, the Royal Danish Academy of Sciences and Letters, the Royal Swedish Academy of Letters, History and Antiquities and the Royal Norwegian Society of Sciences and Letters. He died on 4 April 2018.
