A Count of the Uncountable: Estimates of Undocumented Aliens Counted in the 1980 United States Census

Abstract

This paper presents estimates that show that 2 million undocumented aliens were included in the 1980 US census. Of these 1.1 million were born in Mexico. The estimates derived with a residual method are developed by comparing a census-based estimate of aliens with estimates of the legally resident alien population based on data collected by the US Immigration and Naturalization Service in January 1980. Estimates are presented by age sex and period of entry for all aliens residing in the US for aliens from Mexico and for all other selected countries of origin. In addition to setting a lower limit on the number of undocumented aliens residing in the US in 1980 the estimates provide a framework for assessing the total number of undocumented aliens in the country. These estimates suggest that 46% of the undocumented aliens counted arrived in the US in the 5 years prior to the US Census; thus the Simpson-Mazzoli bill which was nearly passed in 1984 would have excluded recent arrivals from its legalization provisions leaving a sizeable portion of the undocumented population in an illegal status.