The most straightforward interpretation of Professor Romer’s work is that lower interest rates are always going to be more effective at fighting recession than government spending
A second interpretation is that fiscal policy can work but only if that spending is speedy and on a gigantic scale. The first interpretation would lead Ms. Romer, as chairwoman of the economic council, to be skeptical toward a trillion dollar stimulus package; the second interpretation would make her a big spending booster.
http://economix.blogs.nytimes.com/2008/12/02/obamas-most-interestin-pick/