The last real estate bubble was fueled by the ready availability of credit (subprime loans, Alt-A, etc). These buyers today are often paying cash-- i.e. they a

The last real estate bubble was fueled by the ready availability of credit (subprime loans, Alt-A, etc). These buyers today are often paying cash-- i.e. they are on the opposite end of the risk spectrum. They have no incentive to walk away if their house value falls 10%, 20%, 30%, etc.