Jose Luis _ let's call him that _ couldn't return to Mexico for Christmas. He wished he could have; it's been almost a year since he last saw his family. But, for him and 12 million other undocumented immigrants, the risk would have been too high.

The trip to Mexico is not the problem. The real problem lies in returning to the United States after the holidays. Jose Luis couldn't risk being caught by the Border Patrol. Besides, he wouldn't have enough money to pay another "pollero" (immigrant smuggler).

In a recent conversation we had in south Florida, Jose Luis told me how he'd had to pay $3,000 to a "pollero" to help him cross into the United States. He crossed by way of Laredo with false documents. He came into the country by foot. He was lucky; others are forced to cross the desert in Arizona or the mountains in California.

But the crossing is expensive. Before 6,000 National Guard troops were deployed to America's border with Mexico, "coyotes" or "polleros" used to charge Mexicans about $800 for the crossing. Now the price is nearly four times higher.

Anyway, the effort and cost was worthwhile for Jose Luis. Back in Morelia, he earned about $20 a day and could not even afford to buy a car.

"I'd like a minivan to visit my father-in-law in Pena del Panal," he told me, referring to a little town about an hour and a half's walk from where he lives.

Jose Luis, barely 22, misses his four-year old daughter and his three-year old boy, and nothing would make him happier than to take them and his wife to a "jaripeo," a sort of Mexican rodeo. But, he is not about to take such a risk.

He works here as a "finishero," a job in which he puts up walls in new houses, making four to five times more than he would in Mexico. Besides, he's about to pay off his debt with the "pollero" who brought him in, and then he can start thinking of saving money for his van. "I'll go back as soon as I get enough money for my minivan," he said, his unusual green eyes sparkling.

Workers like Jose Luis are becoming increasingly more important to the American economy. Twenty-nine percent of undocumented immigrants are agricultural workers, 25 percent are in cooking and maintenance work, 22 percent are domestic employees and painters, and 14 percent are carpenters, according to the Pew Hispanic Center. Without these immigrants, inflation rates would skyrocket and entire sectors of the American economy would grind to a halt.

What we're seeing after the Sept. 11, 2001, terror attacks is the complete breakdown of the "return home" cycle of undocumented workers. They used to work all year long in the United States and returned to Mexico (and Latin America) for Christmas and New Year. No more. Now, instead of going back, they are trying to bring their families here.

More and more immigrants decide to spend "crismas" in the United States. This also means avoiding the very real risk of dying on the border. Security at the "bordo," as many call it, between Mexico and the United States has been heightened. And so, business for the "polleros" is up. Few dare cross without their help.

Facing tougher law enforcement at the border, immigrants and their guides follow ever more dangerous routes. A GAO report recently revealed that the number of deaths at the border has doubled in the last decade.

The number of immigrant deaths reported in 1998 was 254. The number of deaths for the fiscal year starting in 2006, however, rose to 432.

For all the above reasons _ the pricey "coyotes," a greater chance of being captured and deported, the risk of dying of extreme cold or heat, being run over or getting lost in deserts or mountains, plus widespread poverty in Mexico, and, notwithstanding, well-paid jobs in the United States _ Jose Luis quite justifiably decided not to go back in December.

"I'll stay here for Christmas," he told me. "And if everything goes well, then next year I'll go back and live in Mexico."

"They all say that," I thought. That after a year or two, they'll go back home. But the fact is, that seldom happens. Once they get used to decent salaries, they bring their families in or have children here, it is hard for them to go back to poverty and unemployment.

What Jose Luis does not know is that we all, immigrants like him, said exactly the same thing during our first years in the United States, and then we never returned. But, anyway, the thought of going home next year will help him get through his first Christmas alone in this country.