47% of U.S. households owe no Federal income tax

In 2009, roughly 47% of households, or 71 million, will not owe any federal income tax, according to estimates by the nonpartisan Tax Policy Center.

Some in that group will even get additional money from the government because they qualify for refundable tax breaks.

The ranks of those whose major federal tax burdens net out at zero -- or less -- is on the rise. The center's original 2009 estimate was 38%. That was before enactment in February of the $787 billion economic recovery package, which included a host of new or expanded tax breaks...

The vast majority of households making up to $30,000 fall into the category, as do nearly half of all households making between $30,000 and $40,000...

Of course, income taxes don't tell the whole story. Workers are also subject to payroll taxes, which support Social Security and Medicare.

When considering federal income taxes in combination with payroll taxes, the percent of households with a net liability of zero or less is estimated to be 24% this year, according to the Tax Policy Center's estimates...

A key reason why there is a zero-liability group at all is because the U.S. tax system is progressive. Those who bring in more money pay more than those lower down the income scale to support government functions such as national defense and social safety nets like Medicaid for those in need. That progressivity can be dialed up or down.

"Some think it's too progressive. Some don't think it's progressive enough," said Roberton Williams, a senior fellow at the center...

Experts say that to pay for all the things on the country's growing tab, the money can't just come from a shrunken pool of taxpayers.

"Over the long run, you'll have to have a broader base," Zodrow said.