This video shows Richard Koo debating Ken Rogoff at the inaugural INET conference in 2010. Richard Koo makes a great deal of sense but he has yet to find mainstream support. Rogoff's ideas about debt have since been discredited by a graduate student.
Koo's point that in a balance sheet recession things are different - our attitude to government debt must change. "The is a different disease!" His point is that with private debt levels so high there will be a continuing impact on demand - because the private sector are either paying off debt or saving, government must take up the slack to keep the economy going. Clearly austerity is doing the opposite and prolonging the recession.