Senator Eliot Shapleigh - El Paso, Texas

Despite the recession, the flow of Mexican immigrants out of the United States and back into Mexico has stayed level, according to a report released Wednesday by the Pew Hispanic Center.

The report, which used surveys of families in Mexico, Census data and U.S. Border Patrol data, also found a continued decrease in immigration from Mexico since 2006.

Last year, 433,000 people returned to Mexico, compared with 479,000 two years earlier. The number of people coming in decreased more sharply, with 636,000 people arriving last year compared with nearly 1.03 million two years earlier.

"People are essentially staying put at both ends," said Michael Fix, senior vice president of the Migration Policy Institute, after reading the report. "They're basically riding out the storm."

The findings answer questions that have been raised recently about whether immigrants are leaving the United States because of diminished economic prospects, said Jeff Passel, a senior demographer at Pew.

"It's not surprising, and it fits in well with what we've seen in previous economic downturns," he said, adding that even in a good economy, many Mexican immigrants go back and forth across the border.

About 8 in 10 recent immigrants from Mexico are undocumented, so it is impossible to track arrivals and departures precisely. The report said that although the Mexican-born population in the United States, the country's largest immigrant group, grew in the earlier part of the decade, it has stayed steady in recent years at more than 11 million.

Although the report did not analyze causes for the trend, Passel said reasons could include the faltering Mexican economy; tales of drug violence there putting off returnees; and indications that tougher enforcement by U.S. border patrol agents is keeping people in the United States.

"The monetary cost of getting into the United States, and the danger, have increased," he said, noting that those factors might keep people from crossing the border in both directions. "People who have already spent the money and taken the risk . . . might try to stay here and ride it out rather than spend the money to go back to Mexico and try again at a later date."

Although the numbers still show "a lot of dynamic migration" between the two countries, that may change if the recession continues, said Audrey Singer, a demographer at the Brookings Institution. "If we experience more job loss, we'll see fewer people coming," she said.

Although the report focused only on Mexicans, an October Pew report showed the number of illegal immigrants from other Latin American countries in the United States has also decreased.