According to economists, in the 1980s and 1990s, immigration of low-skilled workers may have increased the labor supply of highly skilled women, and immigration of highly skilled workers may have increased the rate of innovation in the United States.

Migration incentives for working-age and retired individuals are quite different and are sensitive to the level of human capital within the family.

The influx of low-skilled and undocumented workers raises concerns about the impact on low-skilled U.S.-born workers and on the tax burden for all those born in the United States.