Showing that increased immigration tends to benefit natives reduces resistance on the margin, which is worth doing. But, in my experience, laying out clearly the immense benefits to the immigrants is extremely powerful. It highlights the needless misery caused by the heartless status quo. Even then, it is more powerful still to illustrate clearly how the status-quo system of borders, passports, visas, and citizenships systematically violates basic human rights to free movement and association. Will Wilkinson (source)
The statement that migration benefits the migrants is largely self-evident. Migrants wouldn’t migrate if staying home would be more advantageous. Hence, poverty reduction and development aid can benefit hugely from more open borders. What is less clear is that migration can benefit the population of the destination country. There’s a lot of political rhetoric, especially on the extreme right, about the adverse consequences of migration, both economically and culturally. Take for example the talk about unfair competition in the labor market, “importing poverty” and profiteering from social safety nets, the “criminal immigrant” stereotype, Eurabia hysteria etc.
So it’s encouraging to find this useful study:
Using the large variation in the inflow of immigrants across US states we analyze the impact of immigration on state employment, average hours worked, physical capital accumulation and, most importantly, total factor productivity and its skill bias. We use the location of a state relative to the Mexican border and to the main ports of entry, as well as the existence of communities of immigrants before 1960, as instruments. We find no evidence that immigrants crowded-out employment and hours worked by natives. At the same time we find robust evidence that they increased total factor productivity, on the one hand, while they decreased capital intensity and the skill-bias of production technologies, on the other. These results are robust to controlling for several other determinants of productivity that may vary with geography such as R&D spending, computer adoption, international competition in the form of exports and sector composition. Our results suggest that immigrants promoted efficient task specialization, thus increasing TFP and, at the same time, promoted the adoption of unskilled-biased technology as the theory of directed technological change would predict. Combining these effects, an increase in employment in a US state of 1% due to immigrants produced an increase in income per worker of 0.5% in that state.