The role of the ratings agys' "new paradigms" in this whole stinkfest has been somehow massively and conveniently downplayed. Before the explosion in sub-prime lending 2003-2006, it is generally forgotten that in the entire universe there were probably less than 3 dozen "AAA" rated debt securities outside of Treasuries, and I might well be overstating it. And let it be said, they weren't 103% LTV nothing-down mortgage pools on new subdivisions in Fresno, CA. It's pretty easy to see the mechanism of the appraiser who needs to make a living and it's pretty easy to see the loan broker who's in the position of making a quick $6K-$10K on a dirtbag loan, but what went on with the ratings agys was absolutely necessary for this thing to have developed the way and to the extent it did.
Hey, don't be dissing Fresno! It's the home of our very own FreeRepublic. And the housing market is not nearly as bad here as it is in Phoenix!