A while back Krugman published an interesting tabulation of national spending, comparing spending in 2007 with average spending from 1979 to 2007.

In 2007 Consumer spending was 70.3% of domestic demand. The average for 1979 to 2007 was 66.7% and, if Wonks Anonymous youthful boomer memory does not deceive him, this average is high, reflecting the general consumer character of the latest boom. Wonks Anonymous recalls that the rule of thumb for consumption was about 66%. He will try to check this later but not tonight.

Which leads Wonks Anonymous to conclude that we are consuming about 3% to 4% more of our national output than we ought to. Unfortunately we cannot just stop consuming 3% to 4% of national output without creating a rather massive recession. We need to find some other source of demand.

Public investment in education and energy conservation anyone?