Pew Hispanic Center: immigration has not hurt American workers

The Washington Post reports on a new study concluding that American workers have not been harmed by immigrant labor. From the summary of the report, below, I’m not sure how much confidence I have in it. A major limitation of all the immigrant impact studies I have seen is that they do not take into account concentration of immigrant labor in industries which may be in fast growth mode and also cyclical. New immigrant labor in a region may depress wages of Americans in some fields and actually stimulate better wages and job growth for Americans in other fields by providing scarce resources of low wage labor. Skilled American construction workers can be said to benefit by the supply of unskilled and semi-skilled immigrant labor.
The article includes these passages:
High levels of immigration in the past 15 years do not appear to have hurt employment opportunities for American workers, according to a new report. The Pew Hispanic Center analyzed immigration state by state using U.S. Census data, evaluating it against unemployment levels. No clear correlation between the two could be found. Other factors, such as economic growth, have likely played a larger role in influencing the American job market, said Rakesh Kochhar, principal author of the report and an economist at the Pew Hispanic Center.
The study used Census Bureau data to compare the influx of immigrants and unemployment rates in each state between 1990 and 2000, a period of robust economic growth, and between 2000 and 2004, a period of slower growth. “We are simply looking for a pattern across 50 states, and we did not find one,” Kochhar said. “We cannot say with certainty that growth in the foreign population has hurt or helped American jobs.”
In the 10 states with the top employment rates from 2000 to 2004, for example, five states showed a high influx of immigrants while the other five showed little growth in the foreign-born population. “Even in relatively slow economic times, a relationship fails to reveal itself,” Kochhar said.
Some economists expressed reservations about the technique yesterday, arguing that such broad statewide data do not give an accurate picture of immigration’s effects on the labor market. “There’s an age, gender and educational component to this story that this report does not address,” said Andrew Sum, director of the Center for Labor Market Studies at Northeastern University. Between 1990 and 2000, he said, immigrant workers did not take jobs away from American workers “because the strong economy was creating enough jobs to employ everyone who was looking for work.” But in the past five years, a subset of the workforce — native-born men age 16 to 24 with high-school diplomas — have in fact been displaced by immigrants, he said. “We argue that immigrant labor has changed the nature of work in a very negative way,” Sum said.
On the local level, too, some experts disputed the findings of the Pew report. While educated workers with specialized skills are not likely to be displaced by foreign-born workers, young unskilled laborers have felt the pinch in recent years, said Steven A. Camarota, director of research for the Center for Immigration Studies in the District.
A recent study done by the center shows that the immigrant share of the young workforce in Maryland and Virginia nearly doubled in the past five years, peaking at 22 percent and 15 percent, respectively, in 2005. “Native workers who have little education in Maryland and Virginia are dropping out of the labor markets in droves” as the number of immigrants grows, he said. “Unskilled workers only account for a fraction of the total economic output, but if immigration plays a role in even a part of [the trend], that’s something we should be concerned about.”
The report pointed out that immigrants typically move to booming areas of the country with low unemployment rates. “It’s unclear as to whether immigrant workers help to cause that boom, but they certainly haven’t detracted from it,” said Randy Capps, a senior research associate at the Urban Institute.