The FHFA (Federal Housing Finance Agency) released their House Price Index, which measures home price appreciation on single-family homes with conforming loan amounts. Different than Case Shiller, it does not include cash buyers or jumbo loans. The FHFA reported that prices were flat in October after a 0.1% rise in September and are up 11% year over year. Home prices, according to FHFA, are only down 1.1% from their peak. Based on this, you can interpolate that the decline in Case Shiller is coming from higher priced homes where there is less demand.