[15] Moreover, he and Kirchkamp observe that the majority of returnees from Germany to Turkey among Turkish Guest Workers remained economically active, typically as entrepreneurs.
[17] Finally, along with Itzhak Fadlon, Weiss and Dustmann use a Roy model to explore the effect of return migration and skill-specific human capital accumulation on the brain drain in migrants' home countries, which may instead experience a "brain gain" if enough emigrants return after having strongly improved their skills abroad.
[18] A second major area of research in Dustmann's work on migration relates to the effect of immigrants' host country language proficiency.
Among else, he finds that fluency in German among immigrants increases in education, is lower for the elderly and women, and is only improved by labour market participation in the case of speaking.
[21] In work with Arthur van Soest, Dustmann finds that the effect of language proficiency on immigrants' earnings was likely underestimated by earlier studies as the downward bias due to measurement errors in subjective language proficiency dominates the upward bias due to heterogeneity in terms of unobserved ability.
Among else, they find that earlier research in the UK likely overestimated the positive impact of local immigration on natives' attitudes towards immigrants because they omitted the tendency of xenophobic natives to move to locations with few migrants; instead, they find that, if anything, high concentrations of ethnic minorities likely exacerbated xenophobia in England.
[25] With David Card, they also find that xenophobic attitudes among European natives are mainly driven by concerns over how changes in the composition of the local population due to immigration may affect amenities from neighbourhoods, schools and workplaces, instead of concerns over wages and taxes, thus explaining why individuals with lower education tend to display more xenophobic attitudes, as they benefit relatively more from these public amenities than highly educated people.
[27] A fourth area in Dustmann's research on migration studies the impact of immigration on domestic labour markets.
[28] In further work with Albrecht Glitz and Tommaso Frattini, Dustmann studies how European countries' labour markets adjusted to recent immigration through changes in factor prices, output mix and production technology.