Ignore The Case-Shiller Index; Focus On The Future Instead

Case-Shiller December 2010

Last week, Standard & Poor’s released its Case-Shiller Index for December 2010. The index is a home valuation tracker, meant to meausure the change in home prices from one period to the next.

December’s Case-Shiller Index showed major devaluations nationwide. As compared to December 2009, on a year-over-year basis, home values fell in 18 of the Case Shiller Index’s 20 tracked markets, and the U.S. National Index dropped 4 percent overall. 

The retreat puts December’s home values at similar levels as compared to early-2003.

That said, buyers and sellers would be wise to take the findings lightly. The Case-Shiller Index is inherently flawed. As such, its results are neither practical — nor relevant — to everyday Americans.

There are 3 Case-Shiller flaws, in fact.

The first flaw is the index’s limited sample set. Wikipedia lists 3,100+ municipalities nationwide and we can be certain that real estate is bought and sold in all of them. The Case-Shiller Index, however, measures just 20 of them. That’s less than 1% of all U.S. cities. And then, within those tracked cities, Case-Shiller reports an average, lumping disparate neighborhoods and streets into one big number.

The “national figures” aren’t really national, and the “city data” doesn’t apply to your home, specifically.

The second Case-Shiller Index flaw is how it measures home value changes. The index only consider at “repeat sales” of the same home, so long as that home is a single-family, detached property. Condominiums, multi-family homes, and new construction are ignored in the Case-Shiller Index.

Because distressed properties account for such a high percentage of resales lately — 36% in December –foreclosures and short sales skew Case-Shiller Index worse.

And, lastly, the Case-Shiller Index is flawed by “age”. Because it reports closed sales a 60-day delay, December’s Case-Shiller Index is measuring the values of home sales contracts from September and October. The Case-Shiller Index, therefore, is a snapshot of the not-so-recent past, and does little to tell us about the next 60 days.

Overall, the Case-Shiller Index is helpful tool for economists and policy-makers, but it doesn’t do much good for individual homeowners. For accurate, real-time housing data in your local market, talk to a real estate professional instead.

Why You Shouldn’t Put Too Much Faith In October’s Case-Shiller Index

Case-Shiller October 2010

The Case-Shiller Index posted awful numbers in its most recent reading. Each of the index’s 20 tracked markets showed home price deterioration between September’s and October’s respective reports. Some markets fell as much as 2.9 percent.

The drop in values is nothing about which to panic, however. The Case-Shiller Index is just re-reporting what we already knew. It’s a common theme with the Case-Shiller Index, actually; a trait traced to the report’s methodology.

The Case-Shiller Index is an imperfect housing indicator with 3 inherent flaws.

The first flaw is that the index makes use of a limited data set, tracking values in just 20 cities nationwide. That data set is then projected across the more than 3,100 other municipalities in the United States. The “national figures”, therefore, aren’t really national.

The second flaw is that, even within the tracked 20 cities, not all home sales are included. The Case-Shiller Index only tracks sales of single-family, detached homes, and within that market subset, it only uses homes that are “repeat sales”. This specifically excludes sales of condominiums and multi-family homes, and new construction.

Lastly, Case-Shiller Index’s third flaw is its “age”. The Case-Shiller Index reports on a 60-day delay, and the values it reports are tied to contracts written even longer ago.  Sales contracts from July and August are responsible for October’s closings so when we see the Case-Shiller Index as reported in December, some of the data it’s reporting is 5 months old already. That’s too old to be relevant.

Looking back at 2010, housing was at its weakest between May and August. Therefore, it’s no surprise that the most recent Case-Shiller Index shows significant weakness.  Looking forward, we should expect the report to improve — especially because of how strong New Home Sales and Existing Home Sales have been since summer.

The Case-Shiller Index is helpful for economists and policy-makers. It’s not much good for individual homeowners, however. For accurate, real-time housing data, talk to a real estate professional instead.