I'm not sure where you're getting your information, but a few years ago when California was facing a budget crisis, LA Times political columnist George Skelton did some rough math and came up with the following
And by a few years ago, you mean seven? Here is a basic
Wiki synopsis of their economic contributions.
But if you want to stay in 2009, here is Alan Greenspan:
[T]here is little doubt that unauthorized, that is, illegal, immigration has made a significant contribution to the growth of our economy. Between 2000 and 2007, for example, it accounted for more than a sixth of the increase in our total civilian labor force. The illegal part of the civilian labor force diminished last year as the economy slowed, though illegals still comprised an estimated 5% of our total civilian labor force. Unauthorized immigrants serve as a flexible component of our workforce, often a safety valve when demand is pressing and among the first to be discharged when the economy falters.
Some evidence suggests that unskilled illegal immigrants (almost all from Latin America) marginally suppress wage levels of native-born Americans without a high school diploma, and impose significant costs on some state and local governments.
However the estimated wage suppression and fiscal costs are relatively small, and economists generally view the overall economic benefits of this workforce as significantly outweighing the costs.
Then there was
Francine Lipman:
Americans believe that undocumented immigrants are exploiting the United States' economy. The widespread belief is that illegal aliens cost more in government services than they contribute to the economy. This belief is undeniably false... [E]very empirical study of illegals' economic impact demonstrates the opposite: undocumenteds actually contribute more to public coffers in taxes than they cost in social services. Moreover, undocumented immigrants contribute to the U.S. economy through their investments and consumption of goods and services; filling of millions of essential worker positions resulting in subsidiary job creation, increased productivity and lower costs of goods and services; and unrequited contributions to Social Security, Medicare and unemployment insurance programs. Eighty-five percent of eminent economists surveyed [according to the Dec. 1995 study by Julian L. Simon, "Immigration, the Demographic & Economic Facts," of the Cato Institute and the National Immigration Forum] have concluded that undocumented immigrants have had a positive (seventy-four percent) or neutral (eleven percent) impact on the U.S. economy.
Worse still, the
Wall Street Journal surveyed economists and 96% of them said illegal immigration provides a net benefit to the economy. That same survey showed that only 20% of economists believe illegal immigration has a significant effect on lowering wages. The rest said no effect or slight effect.
As far as that silly Heritage study goes, it fails because it basically exaggerates costs while completely ignoring economic benefits. You cannot do a proper cost-benefit analysis if you're going to pretend there aren't any benefits to analyze.
The Real Lesson of the Heritage Immigration StudyEight problems with the Heritage immigration cost estimateHere is one from Fact Check