Here is a summary of conventional economic wisdom:

Many people claim today that the U.S. economy is in a “liquidity trap” and only government can spend us out of this mess. Commentators from Paul Krugman to Martin Wolf of the Financial Times assert we are in a “Keynesian situation”; unless government spending rescues us, we are doomed to suffer decades of economic stagnation.

The above quote is from Liquidity Trap or Malinvested Resources? by William L. Anderson. While he wrote it, it does not reflect his take on the issue. For a simple counterview to this position, read his piece.