By far, the most important factor related to foreclosures is the extent to which the homeowner now has or ever had positive equity in a home.The author looks at other causes but concludes the most important is that:
Stronger underwriting standards are needed -- especially a requirement for relatively high down payments.It makes sense; people are unlikely to walk away from homes into which they have sunk a substantial amount of their hard-earned money. With a requirement for higher down payments, the housing bubble likely wouldn't have happened at all.
The entire article is worth your time.