The history of the US since 2001 is beautifully captured by the graph below. Personal Disposable Income fell after the crash but personal consumption expenditures fell even more. And seven years later the gap is not narrowing. The reason is that a large part of the US population lost years of accumulated saving in the crash and has raised its saving rate to recoup that loss. (According to the Fed's Survey of Consumer Finances 2010, the median US household's net worth fell that year to levels last seen in 1992).

Atif Mian and Amir Sufi in their book, House of Debt, ascribed the gap to households paying down debt contracted during the boom years. But as the graph below shows, the ratio of household debt service payments to disposable personal income is at its lowest level in 35 years. And still personal consumption expenditures have not recovered. So debt is clearly only part of the story.

My new ebook Macroeconomics Redefined has the full story.

P.S. The difference between the saving rates now and before the recession is about 3%. Household consumption accounts for about 70% of US GDP. Multiplying the two we get 2.1%, which is roughly the size of the gap between actual and potential GDP as per Congressional Budget Office estimates