WASHINGTON -- The 16-day shutdown of the federal government last month resulted in $2 billion in lost productivity and, at its peak, left 40 percent of the federal workforce furloughed, according to a report released by the Obama administration Thursday.

Citing previously released estimates from economic analysts at Standard and Poor's, Goldman Sachs and others, the Office of Management and Budget report also predicted the shutdown will reduce U.S. economic growth by as much as six-tenths of a percent, or $24 billion.


The report, which was requested by Sen. Barbara A. Mikulski, a Maryland Democrat, came three weeks after Congress reopened the government through January and extended the nation's debt ceiling following a bruising, partisan battle that led to the first shutdown in 17 years.

The "report is proof-positive that shutdown, slamdown politics is the wrong way to govern our country," Mikulski, the chairwoman of the Senate Appropriations Committee, said in a statement. "This manufactured crisis damaged the economy, cost us jobs, and hurt middle class families."

At its peak, the government furloughed 850,000 of its employees each day, according to the report. About 400,000 of those employees returned to work when Congress and the administration agreed to give the Defense Department flexibility to recall many of its civilian workers.

In all, the shutdown cost the federal government 6.6 million work days, according to the report.

Independent economic analysts such as Anirban Basu of the Sage Policy Group have said Maryland was particularly vulnerable to the shutdown. More than 314,000 residents -- a tenth of the state's workforce -- are employed by the federal government. Another 250,000 work for federal contractors.

Both furloughed employees and those who stayed on the job without compensation received retroactive pay. OMB's estimate of lost productivity is based on the average salary of each agency multiplied by the number of employees who were furloughed.

The total cost of salary for furloughed workers during the shutdown was roughly $2 billion, according to that analysis. Total compensation, including benefits, was about $2.5 billion.

The number of federal workers furloughed each day changed throughout the course of the shutdown, OMB said. The Woodlawn-based Social Security Administration, for instance, recalled over 8,000 workers in the second week of the shutdown to process claim appeals and conduct "other critical work necessary to ensure the timely payment of benefits."

The administration's report comes as lawmakers on Capitol Hill are negotiating a broader budget deal ahead of the next government funding deadline in January.