Estimates of illegal aliens from Mexico counted in the 1980 United States census.

The research reported in this discussion brings together a considerable amount of empirical evidence for estimating the size of the illegal alien population in the US. In particular this research serves to set a lower bound on the number of illegals in the US and shifts the numbers debate to a different set of parameters by presenting estimates of the number of illegal aliens who were included in the 1980 census. The estimates were derived by comparing aggregated 1980 census data for the alien population with independent estimates of the alien population residing legally in the US on the date of the census. The methodology represents an extension of techniques applied by Warren (1982) in analyzing data from the November 1979 CPS. Results are presented by age sex and period of entry for all aliens residing in the US for aliens from Mexico and for aliens from other selected countries of origin. Comparison of the independently derived estimates of the legal alien population resident in the US on April 1 1980 with the census count of aliens indicates that the 1980 census includes at least 2.047 million illegal aliens. Of these 931000 or 45.5% are illegal aliens born in Mexico. Of the illegal aliens present in 1980 890000 or 43.5% entered the US during 1975-80; 551000 or 26.9% entered during 1970-74; 570000 or 27.9% during the 1960s; and the remaining 36000 or 1.9% entered before 1960. The illegals from Mexico present in 1980 are more concentrated in the later periods of entry with 476000 or 51.2% of the illegal Mexicans entering between 1975-80; 280000 or 30.1% entering during 1970-74; and 175000 or only 18.7% before 1970. No single country besides Mexico appears to contribute a substantial proportion of the illegal alien population. Rather all areas which send legal immigrants appear to send illegal immigrants. Of the total estimated number of illegal aliens counted in the census 1.097000 or 53.6% are male. For the Mexican born illegal population counted 531000 or fully 57.0% are male. Overall 18.5% of the illegal population is under 15; 60.0% is at ages 15-34; and 21.5% over age 35. The Mexican born illegal population counted in 1980 is younger and more concentrated in the young adult ages.