Fewer illegal immigrants enter the U.S.

The slow economy and increased enforcement are the main causes of the decrease, researchers say

WASHINGTON -- The flow of illegal immigrants into the United States has declined in the past few years, a study released Thursday found.

The number of illegal immigrants arriving in the United States has dropped from about 800,000 a year earlier this decade, to about 500,000 a year from 2005 to 2008, said the report by the Pew Hispanic Center, a nonpartisan research group in Washington.

The findings reverse a decade-long trend in which more illegal immigrants than legal arrived in the United States.

"These numbers tell us that the growth has slowed substantially," said Jeffrey Passel, a demographer with the Pew Hispanic Center and co-author of the study. "This is a population that had been growing rapidly for at least 15 years, and the growth has essentially come to a halt in 2008."

The total number of illegal immigrants appears to have decreased from 12.4 million in 2007 to 11.9 million in 2008, the study said. However, the finding is "inconclusive" because of the margin of error in the estimates, the study said.

The study did not include any explanations for the decline in the flow of illegal immigrants into the United States, but experts pointed to the struggling economy as a major factor.

The study also found:

* Illegal immigrants make up about 4 percent of the U.S. population and about 30 percent of the nation's foreign-born population. More than 39 million people born in other countries live in the United States.

* The vast majority of illegal immigrants -- four out of five -- come from Latin American countries.

* The number of illegal immigrants from Mexico appears to have leveled off since last year at about 7 million.

Clarissa Martinez, director of Immigration and National Campaigns at the National Council of La Raza, a Hispanic civil rights organization, said the decreased flow of illegal immigrants is about one thing: the economy.

The sectors where illegal immigrants are concentrated -- such as construction and service industries -- were among the first to feel the economic downturn, so it is logical that the flow of people seeking jobs would decrease, she said.

Steve Camarota, director of research at the Center for Immigration Studies, which advocates lower levels of immigration, said stepped up enforcement efforts, including a string of large workplace raids by U.S. Immigration and Customs Enforcement, also had a major impact.

"There are two obvious reasons -- enforcement and the economy," he said.

Camarota said many enforcement efforts, including local ordinances designed to crack down on illegal immigration, are magnified by extensive coverage in the Spanish-language press and have deterred illegal immigration.

The Pew Hispanic Center released another report Thursday that seemed to buoy the theory that the economy is causing the slowdown.

It found that the median annual income of non-citizen immigrant households fell 7.3 percent from 2006 to 2007. By comparison, the income of all U.S. households increased 1.3 percent during the same period.

About half of non-citizen immigrant households are headed by someone in the United States illegally, the report said.

It also found that household incomes have fallen the most for non-citizens who are Hispanic, recently arrived, lack a high school education and are employed in construction, production or service occupations.