WASHINGTON - The system Congress and the Obama administration want employers to use to help curb illegal immigration is failing to catch more than half the number of unauthorized workers it checks, a research company has found.
The online tool E-Verify, now used voluntarily by employers, wrongly clears illegal workers about 54 percent of the time, according to Westat, a research company that evaluated the system for the Homeland Security Department. E-Verify missed so many illegal workers mainly because it can't detect identity fraud, Westat said.
"Clearly it means it's not doing it's No. 1 job well enough," said Mark Rosenblum, a researcher at the Migration Policy Institute, a nonpartisan, Washington think tank.
E-Verify allows employers to run a worker's information against Homeland Security and Social Security databases to check whether they are permitted to work in the U.S. The Obama administration has made cracking down on employers who hire people here illegally a central part of its immigration enforcement policy, and there are expectations that some Republicans in Congress will try in coming weeks to make E-Verify mandatory.
E-Verify correctly identified legal workers 93 percent of the time, Westat said. However, previous studies have not quantified how many immigrants were fooling the E-Verify system. Much of the criticism of E-Verify has focused on whether U.S. citizens and legal immigrants with permission to work were falsely flagged as illegal workers.
Sen. Chuck Schumer of New York, who is writing the Democrats' immigration bill and has fought expanding E-Verify because of its flaws, said Wednesday that the fact that E-Verify was inaccurate so often shows that it is not an adequate tool.
"This is a wake-up call to anyone who thinks E-verify is an effective remedy to stop the hiring of illegal immigrants," Schumer said.
A so-called worker verification process like E-Verify is considered essential to any immigration overhaul proposal that has any chance of approval in Congress.
Westat's report, completed in December 2009 using data from the previous year, was quietly posted on Homeland Security's Web site Jan. 28 along with a summary that pointed out E-Verify is accurate "almost half of the time."
"While not perfect, it is important to note that E-Verify is much more effective" than the I-9 paper forms used by most employers, the summary said.
Rosenblum, who has studied E-Verify, said Westat's evaluation shows it doesn't make sense to substantially expand and invest in E-Verify without fixing the identity theft problem.
Bill Wright, a spokesman for U.S. Citizenship and Immigration Services, said the agency, part of the Homeland Security Department, has created an anti-immigrant identity fraud unit in Buffalo, New York, to address the issue.
The agency is developing a way for people to screen themselves through E-Verify so they can show potential employers they can legally work.
About 184,000 of the nation's 7 million to 8 million employers are using E-Verify, the Homeland Security Department says on its Web site.
Congress gave DHS about $100 million to spend on E-Verify in its 2010 budget.