The recession is starving the government of tax revenue, just as the president and Congress are piling a major expansion of health care and other programs on the nation's plate and struggling to find money to pay the tab.

The numbers could hardly be more stark: Tax receipts are on pace to drop 18 percent this year, the biggest single-year decline since the Great Depression, while the federal deficit balloons to a record $1.8 trillion.

Other figures in an Associated Press analysis underscore the recession's impact: Individual income tax receipts are down 22 percent from a year ago. Corporate income taxes are down 57 percent. Social Security tax receipts could drop for only the second time since 1940, and Medicare taxes are on pace to drop for only the third time ever.

The last time the government's revenues were this bleak, the year was 1932 in the midst of the Depression.

In May the government's best estimate was that Social Security would start to pay out more money than it receives in taxes in 2016, and that the fund would be depleted in 2037 unless changes are enacted.

Some experts think the sour economy has made those numbers outdated.

"You could easily move that number up three or four years, then you're talking about 2013, and that's not very far off," said Kent Smetters, associate professor of insurance and risk management at the University of Pennsylvania.

The government's projections included best and worst-case scenarios. Under the worst, Social Security would start to pay out more money than it received in taxes in 2013, and the fund would be depleted in 2029.

The fund's trustees are still confident the solvency dates are within the range of the worst-case scenario, said Jason Fichtner, the Social Security Administration's acting deputy commissioner.

"We're not outside our boundaries yet," Fichtner said. "As the recovery comes, we'll see how that plays out."

President Barack Obama has said he wants to tackle Social Security next year, after he clears an already crowded agenda that includes overhauling health care, addressing climate change and imposing new regulations on financial companies.