BPO vs Case Shiller vs Zillow – Which valuation is the most reliable

[Brent Hall]

While researching a property that is scheduled for foreclosure auction, I noticed a large discrepancy in the valuation given to the property by the broker (exterior BPO only), the valuation from Zillow using Zillow’s Home Value Index and what the property is worth on a technical basis when utilizing the Case Shiller Index.

The decrease in value of the property vs. the prior sale price is as follows according to the three sources:

BPO: -32%
Case Shiller: - 17%
Zillow: -47%

The BPO is comparing this property to like kind properties within a small radius. Zillow tracks valuations by zip code. Case Shiller tracks valuations by City.

Should the Case Shiller Index continue to have such a big influence on the media and residential real estate market in general?