Economic Impact of Immigrants Unclear

LOS ANGELES -- The debate over immigration reform resumes on Capitol Hill this week _ so brace for a barrage of conflicting claims over whether the millions of people here illegally drain or fill the government's wallet.

Illegal immigrants cost $20 billion each year in education, health care and other public services. They contribute more than $7 billion annually in Social Security taxes they'll never claim.

Those are just some of the statistics that lawmakers and interest groups from both sides will trot out starting Monday when the Senate begins discussing what would be the most sweeping immigration reform legislation in 20 years.

Do illegal immigrants take more than they contribute? Or is it the other way around? Despite volumes of studies cited by both sides, no one knows for sure.

And answers often reflect the opinions of who's talking as much as the reality of illegal immigrants in the United States today, according to academics who study the issue.

"Because of the politically charged nature of this, people are going to cherry-pick their results," said V. Joseph Hotz, a labor economist at the University of California, Los Angeles, who doesn't believe a definitive study is possible.

One reason is the nature of the population in question.

"Anything that is illegal, the data is going to be suspect," said Vernon Briggs, a labor economist at Cornell University who has been studying immigration issues for 40 years.

That won't stop Congress from wrestling with that bottom line and other issues.

Majority Leader Bill Frist, R-Tenn., has said he is committed to passing immigration reform legislation by Memorial Day. The bill up for debate would include additional border security, a new guest worker program and provisions opening the way to eventual citizenship for many of illegal immigrants in the country. The House passed a bill late last year that would criminalize illegal immigrants and those who offer them assistance.

Pressure to act quickly has intensified. A majority of Americans now cite anxiety over immigration as one of the most important problems facing the nation, according to a recent poll by The Associated Press and Ipsos.

Yet compiling hard data has been difficult.