Here's a discussion on the topic, what's interesting is that all of it is really just a bunch of theories it's not a science by any stretch of the imagination. There are just too many variables that could make the theory worthless. The Keynes side seems to think that if you just pump enough money into the economy everything will reach equilibrium and all will be well. The problem with that idea is that it just doesn't seem to work in a debt saturated economy. So what if Ben and Larry Summers are 100% wrong, what then?

Here's the discussion : http://ineteconomics.org/blog/inet/bring....