Migrant workers are overqualified for the jobs they are doing and more educated than their Irish counterparts, according to the findings of an Economic and Social Research Institute (ESRI) report.
As a result, it finds migrant workers are tending to reduce income inequality by limiting growth in earnings for higher-paid skilled workers.
The report says migrants may have significantly benefited the economy during the 1990s.
"The labour market profile of immigrants in Ireland has shown them to be a young and highly educated group.
"If it were the case that immigrants and natives were employed in an identical manner in the Irish labour market, our estimate exercise suggests that immigrants who arrived in the five years between 1993 and 2003 increased GNP by between 3.5 and 3.7 per cent," the report claims.
Had they been largely unskilled, migrants would have impacted negatively on the pay of unskilled workers, but the report says that migrants are overqualified for the jobs they are doing.
"The analysis suggests that immigrants' experience an occupational gap, by which we mean that, controlling for a range of factors, immigrants have lower occupational attainment relative to natives. This is an important finding," it concludes.
The report's findings - which emerged first last year - will be formally accepted for publication in the ESRI's next Economic and Social Review in spring.
The average age of migrants from non-UK EU countries is 28.8 years, compared to 40.8 for Irish workers, the report finds.
It shows that 40 per cent of all migrant workers have a third level degree or higher, compared to just 16 per cent of Irish workers.
The report finds that while 13.7 per cent of Irish workers have no formal or primary education, the number of migrants falling into this category is just 5.5 per cent.
The report confirms findings in the quarterly national household survey that migrant workers are not just working in low wage sectors, but are spread across different sectors of the economy.
But it finds that migrant workers have not gained any advantage from greater educational attainment.
"While immigrants are more heavily represented in the professional/associate professional occupations, this is only marginally the case. Immigrants are less well represented in the management/administrator category," it says.
The share of migrant workers in the top three professional categories is 34.8 per cent, compared to 36.9 per cent for Irish workers.
"The cause of the occupational gap may relate to English language skills. It may also relate to inefficient job search on the part of the immigrants or an inability on the part of employers to evaluate non-Irish qualifications," it finds.
The report was written by ESRI economists Alan Barrett, Adele Bergin and David Duffy.
