Returning male Irish migrants, who are college graduates, earn some 10 per cent more on average than men who graduated at the same time but remained at home, according to new research. For those who left specifically for labour market reasons as opposed to men who emigrated in search of adventure, the wage premium is even higher at 15 per cent.

"This implies that experience abroad is well rewarded in the Irish labour market, at least for men," a recently-published discussion paper on the topic states. However, there is no wage premium for returning female migrants relative to women who never worked abroad. The research suggests that this could be because the women sampled were "tied migrants" whose moves were determined by the labour market considerations of their partners rather than their own.

The research, carried out by Dr Alan Barrett and Philip O'Connell of the Economic and Social Research Institute (ESRI), drew on data collected in 1998 on more than 800 Irish people who had graduated from Irish colleges in 1992.

It classified "returners" as those who had lived outside the Republic for at least six months since graduating but who have since returned to work here.

Among the reasons that returning migrants may earn more is that they may have accumulated additional human capital while away that is rewarded on return.

"By being exposed to different approaches to technical or management matters, emigrants may pick up skills and competencies that are then rewarded once they return to their home countries," the discussion paper says.

The authors also suggest that employers may see time away as a signal for more productive workers and so may offer higher wages to those who later decide to return home.

Finally, those who migrate may have other less obvious characteristics, such as initiative, which also leads them to be more productive.

However, those who move abroad to work mainly out of an interest in seeing the world or experiencing different cultures may not be accumulating additional human capital through work experience, especially if they are working in casual jobs whose only purpose is to support them while travelling.

The research also found that although the computer sector has shown particularly strong growth in the Republic, the premium paid to returning male migrants is not restricted to this business sector.