Unauthorized immigrants make up just more than 3 percent of the U.S. population, But they're accused of sucking up public benefits and dodging taxes. Illegal aliens are tax dodgers. That's one of the most shocking findings of FAIR's most recent report on the "cost of illegal immigration. "Most illegal aliens do not pay income taxes," FAIR reports. "Among those who do, much of the revenues collected are refunded to the illegal aliens when they file tax returns. Many are also claiming tax credits resulting in payments from the U.S. Treasury." The Center for Comparative Immigration Studies in San Diego begs to differ. It found 75 percent of undocumented California immigrants paid income taxes in 2006. In 2007, the Congressional Budget Office reported that about half of all unauthorized immigrants pay Social Security taxes. Using fake Social Security cards, unauthorized immigrants pay into the Social Security unclaimed Earning Suspense File. That kitty had grown to more than $500 billion by 2005, the Immigration Policy Center says. The unclaimed money generated between $6 billion and $7 billion in income for Social Security beneficiaries, along with about $1.5 billion for Medicare, the New York Times reported in 2007. Many economists report that, far from being leeches, immigrants pay more in taxes than they receive in services. Unauthorized immigrants in Arizona, and many legal immigrants, aren't eligible for Food Stamps, Welfare, Medicare, Social Security. They do get emergency Medicaid benefits, if they're poor enough, under certain limited conditions — mortal illness, injuries, pregnancy. In addition, they use hospital emergency rooms less than native-born patients. And since unauthorized immigrants make up a little more than 3 percent of the U.S. population, it's unlikely that they're bankrupting hospitals by invading emergency rooms. (Of course, hospital emergency rooms aren't allowed to ask who is legal and who isn't, so it's a moot point.) "The consensus of the economics literature is that the taxes paid by immigrants and their descendants exceed the benefits they receive — that on balance they are a net positive for the federal budget," the Brookings Institution reports in its recently published "Ten Economic Facts About Immigration."