Well, duh!

Brad DeLong quotes from an article by Jason Furman in the Financial Times:

But the post-crisis experience, as well as research on the effects of fiscal policy, is establishing a “new view” grounded in five principles:

1. At a time when conventional monetary policy faces limitations in a world of lower interest rates, fiscal policy can be a particularly effective complement....
2. In today’s conditions fiscal policy may... “crowd in” private investment through stronger growth....
3. [In] advanced economies... under today’s economic conditions effectively crafted investments could raise output by more than they raise debt--reducing the debt-to-GDP ratio....
4. Prolonged lower interest rates and economies operating below potential suggest that fiscal expansion should be more sustained....
5. Fiscal policy is even more beneficial if co-ordinated more across countries...

To which my reaction (as a lay reader, not an economist) is: Well, duh!  Wasn't all that obvious (except maybe for  #5) seven years ago?