The family of Teresa Martinez, a preschool teacher in Stockton, is living proof of how the nation's economic storm is uprooting immigrants with family ties on both sides of the U.S.-Mexico border.

While it's unclear if anecdotal evidence about Mexicans leaving the United States will eventually add up to a mass exodus, it is clear that those on the move aren't necessarily in this country illegally.

Martinez's two brothers are both legal U.S. residents who earned a good living, she said, working in trucking and construction during healthier economic times in California's Central Valley.

About a year ago, when work dried up, both men decided to ride out the U.S. downturn south of the border, taking refuge in a cheaper, family-owned home in Mexico's northern Sonora state.

Now, however, the brothers – one who has a Mexican law degree – are having trouble finding even low-wage work in Mexico, Martinez said.

Mexico, one of the United States' top trading partners, is one of the most important foreign providers of manufactured goods to U.S. consumers. But U.S. demand is down, and the peso's value has fallen, which not only hurts Mexicans' buying power, but also inflicts harm up north. Mexico is California's biggest export market.

"The crisis is everywhere now. People who were thinking of going to Mexico because they have a family home that would be cheaper to live in now have to think about how they will earn money to buy food," Martinez said.

Plenty of Mexican and U.S. government data are piling up suggesting that the ailing U.S. economy has slowed the flow of Mexican migrants north.

From 2006 through May of this year, for example, the number of people leaving Mexico – including legally – fell by more than 42 percent, according to a report released this month by Mexico's National Institute of Statistics and Geography.

The institute conducts quarterly census studies to track the movement of people in and out of Mexico.

Existing data, though, still isn't definitive about whether scattered anecdotes tell the whole story.

The institute's report says the number of people entering Mexico from abroad – presumably mostly from the United States – shows the flow has held relatively steady since 2006 up to this past May.

"No variations have been detected that signal a massive return of Mexicans," the institute said.

In Sacramento, Mexican Consul General Alejandra Bologna agreed. She said it's premature to conclude a widespread migration back to Mexico is well under way.

She said she hasn't noticed a huge jump in requests for documents – passports, school transfer forms – that might indicate that large numbers of families are leaving.

But dire predictions of the U.S. economy getting worse, have governors in various Mexican states warning that an increase of returning paisanos, or countrymen, would create even more demand for scarce jobs in Mexico.

On Friday, the Mexican newspaper La Jornada reported that directors of a federal public works program plan to encourage returning Mexicans to channel their savings into housing projects that could spur employment for themselves and others.

Many Mexican immigrants send money home to invest in building their own family homes. Officials reason that the returnees' savings – and the skills of those who worked in U.S. construction – could be incorporated into existing programs that match government dollars to Mexican workers' and business' contributions toward home construction.

Martinez said her sister, who is also a preschool teacher in Stockton, is the latest family member considering heading to Mexico.

Her sister's husband is from Jalisco state, Martinez said, and the couple could live in a family home there with their two small children for a while. But they would have to worry about earning cash for living expenses.

Her sister's husband lost a good job in California, Martinez said, when a furniture factory he worked in shut down this year. As a result, she said, the couple lost their home to foreclosure.

Rafael Fernandez, 30, an undocumented immigrant in Sacramento, said he used to earn $18 an hour working for a private company that paved sidewalks, under contract, for the city of Sacramento.

If he can't find more work, he said, he might return to Mexico, too. Lately, he said, he's been able to find only sporadic work as a day laborer.

He doesn't earn much to send his family now, he said, but back in his home state of Michoacán, he might be worse off.

He earned only $10 a day in Michoacán, he said, producing fruits and vegetables that were processed and exported to the United States.

"You feel frozen now," Fernandez said. "You're can't do anything. You can't really go back. You can't find work here."

Call The Bee's Susan Ferriss, (916) 321-1267.