Immigration to Iceland rose rapidly in the late twentieth century, encouraged by Iceland's accession to the European Economic Area in 1994, its entry into the Schengen Agreement in 2001, and the country's early twenty-first century economic boom. Iceland's largest ethnic minority comprises Polish immigrants in Iceland. Immigration has also brought significant new ethno-religious groups such as Jewish people, and new minority religions, including Islam. In 2017, 10.6% of the population were first-generation immigrants. Research on the experience of immigrants to Iceland is in its early days. There is some evidence that racism is not as acute in Iceland as in neighbouring countries. But, while it is popularly believed in Iceland that racism does not exist there, there is evidence that in some respects immigrant populations experience prejudice and inequalities. For example, Iceland has a higher dropout rate from upper secondary school among young immigrants than the EEA average. Due to a shortage of labor, immigration to Iceland will most likely increase in the future. Estimates show that the number of immigrants could be as high as 15% of the total population by 2030. Most Icelandic surnames are based on patronymy, or the adoption of the father's first given name, followed by "son" or "daughter". For example, Magnús and Anna, children of a man named Pétur Jónsson, would have the full name Magnús Pétursson and Anna Pétursdóttir, respectively. Magnús's daughter Sigríður Ásta would be Sigríður Ásta Magnúsdóttir, and would remain so for the rest of her life regardless of marriage. An Icelandic patronymic is essentially only a designation of fatherhood, and is therefore redundant in Icelandic social life except to differentiate people of the same first name the phone directory, for example, lists people by their given name first, patronymic second. Thus it has little in common with traditional surnames except for its position after the given name. It is legally possible in Iceland to rework the patronymic into a matronymic, replacing the father's name with the mother's. Use of the patronymic system is required by law, except for the descendants of those who had acquired family names before 1913 (about 10% of the population). One notable Icelander who has an inherited family name is football star Eiður Smári Guðjohnsen. According to University of Iceland economists Davíd F. Björnsson and Gylfi Zoega, "The policies of the colonial masters in Copenhagen delayed urbanisation.