Time is running out for Congress to extend this year's payroll tax cut past Dec. 31. If it is not extended, many economists would lower their forecasts for 2012, since most assumed it would be extended. Reverting to the previous rate could drain $120 billion from the economy. In addition, $30 billion more is at risk if Congress does not extend long-term unemployment benefits. "It's a meaningful drag," said Joel Prakken of Macroeconomic Advisers.