Yeah it is kind of a chicken/egg situation. But it's not just the amounts being lent out, it's also the ability of sub-prime borrowers to pay the loans back. Mortgages were being mis-sold by unscrupulous lenders, with discounted periods to entice borrowers who might not be able to pay the full rate in the future. And banks had no problem buying these mortgages up and re-packaging them. And this, of course, in turn pushed the house prices up further. And here in the UK, even reputable lenders were offering mortgages of over 100%... madness. So yes, we were overly dependent on property prices - but it's just as unhealthy to have a property market in freefall as it is to have one rocketing upwards.