The report by the Swedish Ministry of Finance's Expert Group on Public Economics (ESO) studied data covering all pupils who completed primary school in Sweden during the period between 1988 and 2014. Results showed significant differences in performance between immigrant and native pupils: while just over 90 percent of all pupils born in Sweden qualify for upper secondary school, for foreign-born pupils the figure drops to 65 percent.
And the difference increased sharply in 2008, "explained by a shift in the demographic composition of foreign pupils in terms of region of birth and age at arrival".
Pupils who moved to Sweden after the typical school starting age of seven, as well as those from disadvantaged socio-economic backgrounds perform particularly poorly according to the study.
Those born in Africa and unaccompanied refugee children have a "significantly higher risk" of failing school. That can be linked to the average age at the time of immigration being higher for those groups compared to other immigrant pupils, meaning they have less time in their new country before they need to complete school.
With a record number of refugee children coming to Sweden in recent years, and an upper secondary school education key to entering the labour market in the country, the current situation could be problematic for integration efforts in the future, researchers warned.
"With many more foreign born students the pressure on society's capacity to integrate increases. Measures need to be broad, targeting students in school but also their parents in order to reduce exclusion," Hans Grönqvist, one of the researchers involved in the report said in a statement.
One of the key findings in the study is that socio-economic status of parents is strongly linked to the size of the performance gap, as is the importance of neighbourhood of residence.
Almost the entire gap disappears if foreign born and native pupils have the same socio-economic background and live in the same neighbourhoods, it observed:
"In particular the analysis shows that the gap decreases when we compare the achievements of immigrant and native students who attend the same schools".
"Broad societal efforts to improve the socio-economic status among immigrants could be a way to improve the school achievement of their children," the researchers concluded.