Comments on Dustmann: Temporary migration and economic assimilation

Most of the research regarding immigration and immigrants to west-ern countries has focused on immigrant performance in the host country and the impact of immigrants on the host country economy. Dustmann (2000) contributes to the large body of literature that has examined the degree of assimilation of immigrants – the rate at which they catch up with equivalent natives in terms of labour earnings. The point of departure from the standard literature is the observation that most immigrants at some point return migrate to their source coun-tries. While this is usually ignored in empirical studies, it turns out that return migration has direct effects on immigrants ’ endogenous accu-mulation of human capital, as well as having important implications for the way in which we measure the rate of assimilation of immi-grants. In order to understand the interaction between human capital ac-cumulation and return migration, one should consider the following key result: human capital accumulation will increase, the later the date of return migration, provided the return to human capital is higher in the host country than in the source country. In other words, the fur-ther into the future the planned date of return, the faster will be the rate of assimilation. It follows that migration restrictions, such as time-limited contract migration or the policy of sending back of refu-gees once source country conditions have improved,1 will undermine the assimilation of immigrants subject to these restrictions. This discussion illustrates that return migrants are generally not representative for their immigration cohort. If one were to measure the assimilation of immigrants without taking return migration into account, one would most likely underestimate the human capital ac-cumulation of those who stay for longer time. Hence, in order to properly estimate assimilation, data on intended date of return migra-tion are needed, otherwise the estimates will be biased. Dustman