A report by the Pew Hispanic Center shows a reversal of a trend that began in the '90s.

By Cynthia Dizikes
Los Angeles Times Staff Writer

WASHINGTON — For the first time in a decade, the makeup of the U.S. immigrant population may be shifting, with the number of illegal immigrants entering the country falling behind the number of those entering legally, according to an independent report released Thursday.

The swing, a possible result of the economic slump and a federal immigration crackdown, marks a reversal of a pattern begun in the 1990s, when the number of newly arrived illegal immigrants surpassed those arriving lawfully, according to the study by the Pew Hispanic Center, a Washington think tank.

"This is a population that had been growing rapidly and substantially for at least 15 years, and the growth has essentially come to a halt in 2008," said Jeffrey S. Passel, a senior demographer at the center who co-wrote the report.

Other recent studies have pointed to possible declines in the number of illegal immigrants living in the U.S. But the Pew study is among the first to show a decrease in the number of illegal immigrants coming into the country.

The report estimates that 11.9 million illegal immigrants were living in the United States as of March, making up nearly 4% of the population.

From 2000 to 2004, about 800,000 illegal immigrants a year entered the U.S., more than 90% of them from Latin America. Since then, the average has dropped to about 500,000 a year. By contrast, legal immigration has remained steady at about 650,000 people a year.

The findings have spurred debate over the reason for the apparent shift. Likely causes include the U.S. economic slowdown and federal enforcement measures such as mass workplace raids, which have been criticized by immigrant advocates.

The economic downturn has had a disproportionate impact on foreign-born Latinos, many of whom work in the housing and construction sectors. The enforcement crackdown came at a time when the economies of Mexico and other Latin American countries have been stable, experts said.

"The climate in the United States is not positive to these workers," said Frank D. Bean, director of the Center for Research on Immigration, Population and Public Policy at UC Irvine. "Whether that is the beginning of a new trend, or an ephemeral result of the labor market, is the question."

Still, the new data suggest that the rate of illegal immigration can vary according to conditions and policies, said Steve A. Camarota, research director at the Center for Immigration Studies, a Washington think tank that favors more controls on all forms of immigration.

"The idea is that illegal immigration is a fact of life, sort of like the weather," Camarota said. "What this suggests is something else, that if you change the incentives, whether it is through enforcement, the economy or some combination of the two, people respond."

Immigration has not been a major issue in the presidential campaign but is likely to confront a new administration and Congress as experts spar over ways to address the issue following the collapse of congressional immigration reform efforts last year.

"People come to work, and they come because there is a job. They are not accidental tourists," said Angela Kelley, director of the Immigration Policy Center in Washington, who added that she believes the economy is the primary factor driving down numbers of illegal immigrants.

Camarota said increased law enforcement had also played a vital part.

"Even a small increase in enforcement can have a huge impact on behavior," Camarota said. "If you pull one person over for speeding, everybody slows down."

Another study released Thursday by Pew points to the disproportionate effect of the economic downturn on "noncitizen immigrant households." At the same time that the median annual income of all U.S. households increased, noncitizen immigrant households saw their incomes fall from about $40,600 to about $37,600 in 2007. Of those, nearly half were headed by an illegal immigrant.

cynthia.dizikes@latimes.com