As an active rain member I have researched historical home price declines for statistical patterns.  The last time we had www.appraisal-values.com excuse me home property values drop was in 1987, when the stock market crashed.  At that time a median property value range of 10% year over year for three consecutive years.  This is based on facts, by local Bergen County Real Estate Agents according to www.BergenCountyMLS.com.  As far as I can see we have seen on average 10% this leaves about a 15% to 20% continued decline if history repeats itself.  But wait a minute, we have had a fox in the hen house too long with Wall Street continuing their churn on the mortgage lending barel with toxic 100 to 110% LTV loand products this go around.  So my estimate is probably 25% before we hit the floor and propery values stabilize.