If you've been wondering where Davis's $9 billion "overcharge number" number 
comes from, attached is  the apparent basis of the number, which was from a 
study prepared by Hildebrandt of the CAISO. It was apparently released on the 
CAISO site on 6/21.  

Note that the $9billion includes bilateral trade sold to any party.  However, 
Hildebrandt cannot say who the supplier is unless DWR, CAISO, or the PX was 
the buyer (for those buyers he presumably has detailed data).  Thus, he can 
ascribe overcharges to specific jurisdictional generators for only $5.4 
billion of the $9billion total.  He does not show what specific parties are 
attrributable to the $5.4 billion.   In an earlier study on just ISO R/T 
"strategic bidding", supplier names were released inadvertantly by CAISO.

Finally, as in previous CAISO studies, a significant fraction of overcharges 
(approx $3 billion)  comes from before the refund-effective date of 10/1/00.

Alan Comnes