Heer D M
Demography. 1979 Aug;16(3):417-23.
Senior government officials have claimed that in recent years an average of 1.4 million illegal aliens have entered the United States annually without apprehension. This conjectural figure does not take into account the fact that the net flow of immigrants is always less than the gross flow. In this paper, seven estimates are made concerning the net flow of undocumented Mexican immigrants to the United States in the period 1970--1975. These estimates are based on the growth of the population of Mexican origin according to the Current Population Survey. According to these estimates the annual net flow ranged from 82,300 to 232,400 persons.
政府高级官员声称，近年来平均每年有140万非法外国人进入美国而未被抓获。这个推测数字没有考虑到移民的净流入量总是小于总流量这一事实。在本文中，对1970年至1975年期间无证墨西哥移民流入美国的净流量进行了七次估算。这些估算是根据当前人口调查中墨西哥裔人口的增长情况得出的。根据这些估算，年净流量在82300人至232400人之间。
