International migration, economic policy and human capital accumulation: a simulation study.

"This paper examines the economic policy implications of international migration and human capital accumulation within a dynamic general equilibrium model. Each country produces by means of physical and human capital of two types (skilled and unskilled labour). Along optimal growth paths in a world of diverging population growth rates immigration can only be beneficial when the free rider effect (i.e., not paying for training costs) exceeds the capital dilution effect of an increase in population growth. Under quite general conditions the optimal immigration rate is zero."