Using census and survey data to measure undocumented immigration and emigration for the United States

Abstract

Developing estimates of emigration and undocumented immigration, generally unknown flows, is critical to census coverage evaluation in the United States. A residual methodology compares census or survey data on the resident foreign-born population with an independently derived estimate of the legally resident foreign-born population. The difference is the estimated undocumented population which may be compared for alternative dates to derive measures of change. In 1988, this difference was 1.9 million, similar to the 1980 estimate of 2.1 million. The apparent lack of growth is principally due to the legalization of about 1.7 million aliens who showed proof of continuous residence in an unlawful status since before 1982. Measurement of emigration – the other unknown – has recently relied on resident reports of immediate relatives who have emigrated. Controlling for multiple reporting of the same emigrants, the direct estimate of the emigrant population from the United States is about 1.2 million. Allowing for undercoverage of the emigrant population due to nonresident relatives, there could be 2.0 million or more emigrants.