A study conducted by the Pew Hispanic Center found that immigrants have no clear effect on the employment prospects of native-born Americans.  The study used census figures and looked at both workers with less than a high school degree and workers ages 25 to 44 with a high school degree but no further education.  The study covered the years 1990 to 2000 and 2000 to 2004 in an effort to capture the contrasting job markets. The Pew study did not distinguish between legal and illegal immigrants.  

In eight states, the study found above-average growth in the immigrant population and below-average employment rates for those born in the United States .  However, in 14 states the study showed above-average immigration and above-average employment rates for U.S. born workers.  Rakesh Kochhar, the Pew Hispanic Center ’s associate director for research, explained these results by suggesting that economic factors in those states explain the employment rates there.  

The Washington Times this week reported as well on a similar study by the Center for Immigration Studies (CIS) which argued that the Pew study did not look at the native population most likely to be hurt by competition from immigrants.  Steven A. Camarota, research director for CIS, argued that "the big declines in work are among natives who have less than a high school degree or only a high school degree and are young, and [the Pew study] is not really looking at that population."  The CIS report found that between 2000 an 2005, 4.1 million immigrants arrived in the work force, accounting for 86 percent of the growth in employment, the highest recorded share in U.S. history.  At the same time the number of employed native-born men ages 16 to 35 dropped by 1.7 million.  The study also found that unauthorized immigrants account for 56 percent of the net increase in civilian employment during the past five years.  

President Bush has said that immigrants are doing jobs Americans will not do, a central plank to his argument for an immigration overhaul, including an expanded guest worker program.  A Senate bill that has stalled in Congress also calls for a new law that would give millions of unauthorized immigrants working papers.  

The Pew study can be found at http://pewhispanic.org/reports/report.php?ReportID=69 .