STOCKTON, Calif. Since illegally crossing the Mexican border into the United States six years ago, Angel Martinez has done backbreaking work, harvesting asparagus, pruning grapevines and picking the ripe fruit. More recently, he has also washed trucks, often working as much as 70 hours a week, earning $8.50 to $12.75 an hour.
Not surprisingly, Martinez, 28, has not given much thought to Social Security's long-term financial problems. But Martinez who hiked for two days to enter the United States contributes more than most Americans to the solvency of the nation's public retirement system.
Last year, Martinez paid about $2,000 toward Social Security and $450 for Medicare through payroll taxes withheld from his wages like those of any other worker. Yet unlike most Americans, who will receive some form of a public pension in retirement and will be eligible for Medicare as soon as they turn 65, Martinez is not entitled to any benefit.
As the debate over Social Security heats up, the estimated 7 million or so illegal immigrant workers in the United States are now providing the system with a subsidy of as much as $7 billion a year.
While it has been evident for years that illegal immigrants pay a variety of taxes, the extent of their contributions to Social Security is striking: The money added up to about 10 percent of last year's surplus the difference between what the system currently receives in payroll taxes and what it doles out in pension benefits.
Illegal immigration, said Marcelo Suarez-Orozco, co-director of immigration studies at New York University, could provide "the fastest way to shore up the long-term finances of Social Security."
It is impossible to know exactly how many illegal immigrant workers pay taxes. But according to specialists, most of them do. Since 1986, when the Immigration Reform and Control Act set penalties for employers who knowingly hire illegal immigrants, most immigrants have been forced to buy fake IDs to get jobs.
Available for about $150 on street corners in just about any immigrant neighborhood in California, a typical fake ID package includes a green card and a Social Security card. It provides cover for employers, who, if asked, can plausibly assert that they believe all their workers are legal. But it also means that workers must be paid by the book payroll tax deductions and all.
IRCA, as the immigration act is known, did little to deter employers from hiring illegal immigrants or to discourage them from working. But for Social Security's finances, it was a great piece of legislation.
Starting in the late 1980s, the Social Security Administration received a flood of W-2 earnings reports with incorrect sometimes simply fictitious Social Security numbers. It stashed them in what it calls the "earnings suspense file" in the hope that someday it would figure out whom they belonged to.
The file has been mushrooming ever since: $189 billion worth of wages ended up recorded in the suspense file over the 1990s, two and a half times the amount of the 1980s.
In the current decade, the file is growing, on average, by more than $50 billion a year, generating $6 billion to $7 billion in Social Security tax revenue and about $1.5 billion in Medicare taxes.
In 2002 alone, the last year with figures released by the Social Security Administration, 9 million W-2s with incorrect Social Security numbers landed in the suspense file, accounting for $56 billion in earnings, or about 1.5 percent of total reported wages.
Social Security officials do not know what fraction of the suspense file corresponds to the earnings of illegal immigrants. But they suspect that the portion is significant.
"Our assumption is that about three-quarters of other-than-legal immigrants pay payroll taxes," said Stephen C. Goss, Social Security's chief actuary.
Other researchers say illegal immigrants are the main contributors to the suspense file. "Illegal immigrants account for the vast majority of the suspense file," said Nick Theodore, the director of the Center for Urban Economic Development at the University of Illinois at Chicago. "Especially its growth over the 1990s, as more and more undocumented immigrants entered the work force."
Using data from the Census Bureau's current population survey, Steven Camarota, director of research at the Center for Immigration Studies, an advocacy group in Washington that favors more limits on immigration, estimated that 3.8 million households headed by illegal immigrants generated $6.4 billion in Social Security taxes in 2002.