Three essays on international migration.

Summary The subject of international migration has recently received unprecedented attention in both public opinion and the media. However, if the debate on the effects of international migration seems more topical than ever, it has already attracted the attention of economists for several decades. The present thesis thus fits into the economic literature on the effects of international migration by proposing three empirical essays on the implications of human mobility, both for migrants, natives in their host country and their relatives left behind in their country of origin. Chapter 2 empirically revisits the impact of multiculturalism (measured by an index of diversity within the migrant group and by contamination effects) on the macroeconomic performance of American states over the period 1960-2010. We distinguish the effects of multiculturalism by levels of education, controlling for standard variables in the growth literature as well as for unobserved heterogeneity and controlling for migrants' legal status as well as their age of entry into the United States. In order to identify a causal effect, we compare several different identification strategies from the existing literature. Our results converge on a robust positive and significant effect of diversity among tertiary graduates on GDP per capita. No effect of diversity for lower levels of education, or spillover effects are found. Chapter 3 adds to the literature on the determinants of migrants' labor market performance in their host country. We examine whether or not the attitude of natives affects the unemployment durations of migrants in Germany. Using individual-level panel data (GSOEP) over the period 1984-2012 and a duration model, we find that lower levels of native trust in residents of a given country (measured using Eurobarometers surveys) are associated with longer unemployment durations for migrants from that country. Our results highlight the fact that different groups of immigrants face different obstacles to labor market integration depending on their origin.Chapter 4 seeks to understand whether or not international migrants contribute to technological progress in developing countries by inducing a transfer of productive knowledge from their host country to their country of origin. Using an indicator for each country's level of productive knowledge (CIS) and bilateral stocks of migrants to 20 OECD countries, we show that international migration is an important channel for technology transmission.