A new World Bank policy brief reviews the effects of immigrants on productivity:
For a sense of net effects –positive or negative, we looked at 22 primary studies. Explicit analysis on skilled versus unskilled immigrants is rare. So, most of the econometric results pertain to the effects of total immigrants. They remain instructive, given the overwhelming direction of migrant flows from less educated to more educated countries.
…In our RPB, broken down to the three components of labor productivity, positive effects from total immigrants are especially apparent through TFP. There is no statistically significant impact on physical capital per worker suggesting that capital accumulation need not be adversely affected. Human capital per worker is somewhat negatively affected, indicating that immigrants’ compositional effect on skills tends to outweigh the effect on natives’ skills upgrading. In the studies that analyze labor productivity alongside all its three components, positive immigrant effects on TFP more than offset the effects on physical capital and human capital per worker.
Outcomes vary across countries. Positive productivity effects from total immigrants are obvious for the U.S. – analysis using state-level data links task specialization of less-educated natives, induced by unskilled immigrant inflows, to TFP growth. Studies suggest that the complementarity and scale channels operate in Malaysia, but also that automation is somewhat hindered. Actual empirical evidence of net productivity effects seems mixed, and not representative enough of the economy as a whole, tending to focus on the manufacturing sector. In contrast, there is also the unique example of a large influx of skilled immigrants into Israel (fleeing the collapse of the Soviet Union) not having positive effects on productivity in the manufacturing sector.
More than anything, the cross-country evidence highlights that underlying the likelihood of positive net productivity effects is how immigrants link to specific gaps in the economy – regardless of skill level. And the response of agents, markets and institutions in host countries.
In fact, the report found that “on balance, total immigrant effects on labor productivity are statistically insignificant to positive” with “statistically significant positive effects” for total factor productivity (pg. 2). In short, “The economic case for an outright ban on unskilled immigrant workers is weak.”
And now I’ll leave you with the Hamilton Mixtape.