"We know undocumented immigrants already pay 6 or 7 percent of their income in state and local taxes, simply because they buy things and rent or own homes, and sales and property taxes are paid automatically," said ITEP executive director Matthew Gardner. Legalization is projected to boost wages and income tax compliance, he said, producing "substantial new revenues" for the states.
According to the study, based on payments in 2010, an estimated 550,000 undocumented immigrants live in New Jersey, 160,000 in Pennsylvania, and 25,000 in Delaware.
Collectively, they pay $476 million annually in state and local taxes in New Jersey, $149 million in Pennsylvania, and $12 million in Delaware.
In most cases, according to the study, payroll taxes paid by workers here illegally would more than double if Congress passes immigration changes.
Legislation to toughen border security and grant legal status to most undocumented immigrants, with a pathway to citizenship, recently passed the Senate and awaits action in the House.
The ITEP and White House studies are the latest of several reports released this year on the projected impact of immigration changes.
Pushing back against the Senate bill are opponents of granting undocumented immigrants citizenship, who cite a study by the right-leaning Heritage Foundation that estimated legalization would cost $6.3 trillion over 50 years due to increased use of public services and benefits.
According to that study, a household headed by an undocumented immigrant lacking a high school diploma receives $25,000 a year in public education, public-safety services and other benefits, while it pays just $10,000 a year in taxes.
Meanwhile, the independent Congressional Budget Office estimates that enacting the Senate's bill would reduce the federal deficit by about $200 billion over the next decade.
What can the public conclude from the avalanche of numbers?
"Immigrants in general aren't all that different from the population as a whole," said University of Pennsylvania professor of management Peter Cappelli, an expert on the economic aspects of immigration. But undocumented immigrants, he said, are likely to have less education and lower skills.
"If we added more of these folks to the legal economy," he said, "would it help? Compared to what? To having them here anyway, and illegally? I don't think there is any doubt that making them legal is better. You collect the taxes."
Contact Michael Matza at 215-854-2541, firstname.lastname@example.org, or follow on Twitter @MichaelMatza1