Home value indexes

The S&P Case-Shiller index of home values posted an annual drop of 18% (high: Phoenix -32.7%, low: Dallas -3.0%) yesterday. But what goes into an index of home prices?

• Which geographic regions are covered
• Property value weighting (do more expensive homes have a larger impact on the index)
• Are appraisal values included rather than just sales transactions
• Are houses financed with subprime mortgages and/or non-conforming loans (jumbos) included
• Should foreclosed homes sales be included, given that they may not represent a normal transaction

Here's the Wall Street Journal's look at several different home value indices from November.