Mexican immigrants, highly concentrated in low-skill professions, earn an average $22,138 each year. That's roughly $15,000 less than immigrants from other countries, the report says. The recent Inter-American Development Bank survey found that 61 percent of Mexicans earned less than $20,000.

For Luis Montoya, 40, who migrated to Salt Lake City to support his wife and toddler son in Mexico, a job at a local car wash allowed him to send home $300, $400, sometimes $500 a month.

Recently, Montoya smiled as he pointed to two mattress pads propped against the wall in the living room of the cramped one-bedroom apartment he shared with three other immigrants.

"Muy chiquito," he said, Spanish for "very tiny."

Montoya recently returned to his hometown of Santa Rosa, Zacatecas, to meet his 2 1/2-year-old son for the first time. In Salt Lake, he says, he found it "very difficult" to be so far away from his family. But it was too dangerous for them to cross the border; and, he said, it's too difficult to earn a living at home.

In Santa Rosa, Montoya's brother, Baudelio Montoya Miranda, 47, describes how he traveled twice to Utah to work. In Mexico, he says, he makes 300 pesos a week, roughly $27, operating a small farm store.

That compares to the $5.75 an hour working at a Salt Lake restaurant, which enabled him to send home about $200 a month of the $450 to $600 he earned. His life in Mexico is simple, he says, but sufficient. "I eat well," he says. The family's meals consist primarily of beans and corn.

Because it's not possible to get papers to legally immigrate to the United States, he says, the next best option is to cross the border.

A dwindling population

But crossing the border is dangerous. When Baudelio Montoya swam across the first time, he was detained for three months.

The second time, he crossed on foot through the Arizona desert.

When asked if he'd cross again, he answers, "If there are possibilities, yes, but I am waiting for paperwork, for amnesty."

People get assaulted, he says, by "cholos," or thugs. And it's frustrating to listen to the radio and hear Congress debate the issue. One day, they're going to sort it out, and the next day they're not.

He says it costs about $2,000 to $3,000 to pay a smuggler each time he crosses the border. Once in the United States, it costs about $100 to buy a Social Security number to get a job.

"The burden is on them up there," he says. "If you're a good worker, they'll always take you."