18 by counting them first as illegal immigrants when they arrive in the United States and again as legal immigrants when they acquire permanent resident status.

Recent estimates of the undocumented population counted in the 1980 census and in the Current Population Surveys suggest that the number of undocumented immigrants is growing. Passel and Woodrow (1986) estimated that the undocumented population grew by 100,000-300,000 annually between 1979 and 1983. More recently, it has been estimated that by June 1986 the illegal population was probably growing by 100,000-200,000 persons per year (Woodrow, Passel, and Warren, 1987a,b). On the basis of these and other studies, I would recommend a level of net illegal immigration of 150,000 per year. A smaller figure than that would be inconsistent with the large number of illegal immigrants who have taken advantage of the amnesty provisions of the Immigration Reform and Control Act of 1986. No information is available on the year that l_galization applicants first arrived in the United States or established residence, but applicants were asked for their year of last entry to the United States. For persons applying for amnesty by October 1987 (about half of the total applying through the end of the program), about one-third last entered the United States between mid-1980 and mid-1985 (Hoefer, 1988). An additional 5 percent said they last entered after mid-1985 (although they are required to have been living in the United States cortinuously since January 1, 1982 in order to qualify for amnesty). Overall, 89 percent of the Special Agricultural Workers (SAW applicants) last entered the United States after January 1, 1982. If these same percentages hold true for all amnesty applicants, then it is clear that gross illegal immigration in the 1980s must be considerably higher than 100,000 annually. In fact, the United States Bureau of the Census now uses a net illegal immigration figure of 200,000 per year for each year since 1980.

The Immigration Reform and Control Act was designed to reduce the future incidence of illegal immigration. It appears, however, that illegal flows are continuing to be strong. New illegal immigrants may find it more difficult to obtain factory jobs but there will continue to be ample jobs in the informal sector for the foreseeable future. Given the income disparities between the source countries for illegal immigrants and the United States, it is unlikely that the annual flow of undocumented immigrants will fall substantially before the year 2000.

Little is known about the characteristics of undocumented immigrants. There is a consensus that a majority of illegal immigrants (probably about 60 percent) are Mexican. The illegal flow also appears to be disproportionately male. Of the 2.06 million illegal aliens counted in the 1980 census, 53 - percent were male (sex ratio 114). The sex ratio is even higher for illegal immigrants from Mexico (131 for those who entered from 1975 to 1980). It is probable that the sex ratio is somewhat higher for undocumented immigrants not counted in the census since they are likely to be more transient. Therefore, an overall sex ratio of about 120 seems most defensible.

The political and economic climate. In recent years, less than 20 percent of legal immigration to the United States has originated in economically developed countries. There is no question that economic