Orszag, 41, came to Obama's government from the position of director of the Congressional Budget Office, the agency charged with providing nonpartisan analyses of economic issues to lawmakers. He served during Bill Clinton's administration as an assistant to the president for economic policy and a senior adviser at the National Economic Council.
The move comes as Obama continues to face the steep economic challenges of reining in the deficit and rallying support for more stimulative spending. The economic recovery is plodding along but unemployment remains near 10 percent.