Migration, unemployment and growth.

Summary This thesis studies the relationship between migration, unemployment and growth. The first part evaluates the arguments for the location choice of workers and the selectivity of migration. The second part focuses on the relationship between migration and unemployment. A summary highlights three limitations of previous work, which chapters 4 and 5 attempt to address. These chapters consider that not all local labor markets are competitive, as wages are negotiated. The determinants of location choice are extended to migration costs and land rents in addition to employment opportunities and wages. Transitional dynamics are also studied. The following results are demonstrated. Labor mobility does not exclude the persistence of unemployment rate differentials. The opening of borders can increase or decrease the general level of unemployment. It can induce an over-adjustment of the unemployment rate of the receiving region and an under-adjustment of that of the sending region. Finally, it always increases the welfare of the most disadvantaged workers. The last part is devoted to the relationship between migration and growth. Previous theoretical work, summarized in chapter 6, concludes that the immigration of low-skilled workers has a negative impact on the welfare of the host region, while the emigration of skilled workers is generally considered detrimental to the region of departure. Two original contributions put these conclusions into perspective. First, it is shown that low-skilled immigration can induce more workers to train, which is a favorable consequence for the growth of the host region. Furthermore, we show that skilled migration may be desirable if the sending country can imitate the technological advances made in the receiving country and if the emigrants send remittances to their home region.