From Bloomberg.com:

http://www.bloomberg.com/news/2014-09-03/case-shiller-retrofit-shows-less-severe-u-s-home-price-slump.html

The collapse in U.S. home prices that stoked the worst recession since the Great Depression wasn’t quite as severe as initially estimated, according to data from S&P/Case-Shiller.

Property values nationally fell 26 percent from the February 2007 peak to the December 2011 trough, not 34 percent as previously reported, revised data showed last week. The index will now be issued monthly rather than quarterly.

The change is the result of CoreLogic Inc. (CLGX)’s $6 million purchase of the S&P/Case-Shiller index from technology company Fiserv Inc. in March 2013. Case-Shiller has spent more than a year retrofitting its model with CoreLogic’s bigger, higher-quality data set, leading to a change in how the index looks.