and more reactive to regional wage differentials. In migration literature it is a standard
proposition the fact that economic migrants2 tend to be, on average, more skilled, young,
educated and entrepreneurial than similar individuals who choose to remain in their place of
origin (positive self-selection of the migrants).3 A better understanding of the pattern of
migration is important for assessing the economic and sociological consequences for the
origin and destination regions. The more migrants are favourably selected and the more
beneficial will be their impact on the destination economy. On the contrary, the more
positively selected are the migrants the greater, in general, will be the adverse effect on the
region of origin.4
Modern economies have made an epochal transition from a world where the basic
source of value, productivity and economic growth has been physical labour and manual
skill, to a world of knowledge-intensive capitalism where a fundamental role is played by
intelligence and intellectual labour (human capital). Scientists, engineers and high skilled
workers on the factory floor and in advanced services companies are the sources of
innovations and ideas. The wealth of regions and nations in the 21st century economies is
largely based on this human infrastructure (Florida, 1995). Consequently, a region with a
more skilled labour force is likely to grow faster than a region with a less skilled labour force.
Migration of high skilled workers may potentially have consequences on the regional
2 We refer to economic migrants as individuals who move from one place of work and residence to another,
both within or across countries, on the basis of a decision taken comparing their own economic opportunities in
origin and destination locations. In this way we want to distinguish those migrants from refugees and those
migrating for other reasons.
3 For a review of theoretical and empirical contributions on this topic see Chiswick (2000). Borjas, Bronars and
Trejo (1992) find evidence of self-selection studying internal migration in the U.S. In fact migrants with higher
educational levels appear to be attracted toward regions with higher returns to education.
4 According to some authors (see Mountford 1997, or Stark et al 1997), when migration is not a certainty, the
brain drain may be associated with a brain gain for the source region. The possibility to migrate gives an
incentive to invest in human capital formation. Therefore, higher levels of human capital in the economy could
outweigh the negative effects of the brain drain. While this outcome may, in principle, be realistic when
assessing the effects of North-South migration, it seems to be less appropriate when applied to migration flow
between and within developed countries.