A 2018 study found that the "presence of immigrant students who have been in the country for some time is found to have no effect on natives. However, a small negative effect of recent immigrants on natives' language scores is reported." Another 2018 study found that the presence of immigrant students to Italy was associated with "small negative average effects on maths test scores that are larger for low ability native students, strongly non-linear and only observable in classes with a high (top 20%) immigrant concentration. These outcomes are driven by classes with a high average linguistic distance between immigrants and natives, with no apparent additional role played by ethnic diversity."