The U.S. unemployment rate would again exceed 9 percent if Congress allows the tax increases and spending cuts that make up the “fiscal cliff” to go forward, the nonpartisan Congressional Budget Office (CBO) said Thursday.

The CBO had already estimated that going over the fiscal cliff would spark a recession, while simply voiding the tax increases and spending cuts would add trillions to the debt, The Hill reported. But the new study breaks down in specific detail the cost and benefits of allowing various parts of the fiscal cliff to remain in place.

It finds that unemployment would rise from 7.9 percent to 9.1 percent by the end of 2013 if the nation goes over the cliff.

The analysis comes as President Barack Obama, Senate Democrats and House Republicans gird for a huge negotiation over spending and tax policy in the coming lame-duck session of Congress.

Bush-era tax rates are set to expire at the end of the year, which would raise rates on most households and businesses. A payroll tax cut in place for two years is also set to expire, and Congress has yet to pass legislation to prevent millions of people from being hit by the Alternative Minimum Tax.

Spending cuts triggered by last summer’s debt deal are also set to begin in January.