In his final speech as Fed Chair, Ben Bernanke identifies the No. 1 thing that's caused the economy to be so slow: not enough government spending. He specifically calls fiscal policy "excessively tight."
To this list of reasons for the slow recovery--the effects of the financial crisis, problems in the housing and mortgage markets, weaker-than-expected productivity growth, and events in Europe and elsewhere--I would add one more significant factor--namely, fiscal policy. Federal fiscal policy was expansionary in 2009 and 2010. Since that time, however, federal fiscal policy has turned quite restrictive; according to the Congressional Budget Office, tax increases and spending cuts likely lowered output growth in 2013 by as much as 1-1/2 percentage points. In addition, throughout much of the recovery, state and local government budgets have been highly contractionary, reflecting their adjustment to sharply declining tax revenues. To illustrate the extent of fiscal tightness, at the current point in the recovery from the 2001 recession, employment at all levels of government had increased by nearly 600,000 workers; in contrast, in the current recovery, government employment has declined by more than 700,000 jobs, a net difference of more than 1.3 million jobs. There have been corresponding cuts in government investment, in infrastructure for example, as well as increases in taxes and reductions in transfers.