housing market is driving by "Psychological Boom"

--how does it become an fundamental issue: investors are stretching to buy a house when they assume the price will go up. When they realize they have negative home equity they will default. --how is housing market impacting overall economy: more than half of economy is related to housing market, mortgage, banks, constructions. Now the issue in housing maket is no longer subprime issue, it is impacting even Jumo mortgage. The result is that whole housing market tanker and economy will enter into recession.