Everyone knew housing was a bubble and so was credit. Just like the dot com boom. Anyone can predict its a bubble. Oil and Gold are there now. The hard part is figuring out when that bubble is going to pop.
Dont you agree?
I certainly agree that gold is a bubble. Oil not yet. But I don't agree that many people predicted that housing and the financial markets were a bubble prior to September 2007. Krugman certainly did not despite his claims to the contrary.