Immigration is a phenomenon of growing significance in many countries. Increasing social tensions are leading to political pressure to limit a further influx of foreign-born persons on the grounds that the absorption capacity of host countries has been exceeded and social cohesion threatened....

The number of immigrants across the world has doubled since 1980. The estimates of the impact of immigration on wages and employment in host countries are quantitatively small but vary widely. We use meta-regression analysis to show how the estimates vary with definitions of the labor market,...