Keynes is well-known for the belief that spending drives an economy, and is the reason for my use of his quote in the 7/7/13 post below. Any type of spending --- household, business, government, or foreign --- will all work, though certain types of spending might have a larger ultimate effect.
Though Keynes is often credited with advocating government spending, in fact, he proposed that private sector spending (mostly household + business) was/is preferable for reducing unemployment. The point is that, in his opinion, spending (i.e., effective demand) is what moves the economy the most.
An aside:
Do keep in mind that I'm talking about the entire economy from a macro perspective, not whether a household should or shouldn't have saving and debt-reduction goals. Saving is indeed good for an individual household, but if all households decide to save more, the economy will suffer as a result.
