Case-Shiller is a Misleading Indicator of Current Housing Market

by Tyler Osby on February 1, 2012

November 2011 Case-Shiller Released-Published on 60 Day Delay

The index mea­sures the change in home prices from month-to-month, and year-to-year, in select U.S. cities.

Accord­ing to the data, for the sec­ond straight month, home val­ues fell in 19 of the Case-Shiller Index’s 20 tracked mar­kets. In addi­tion, also for the sec­ond straight month, Phoenix, Ari­zona was the lone Case-Shiller-tracked city in which home val­ues rose.

Over­all, November’s Case-Shiller Index showed a 1 per­cent decrease in home val­ues between Octo­ber and Novem­ber 2011, and a near-4 per­cent decrease between Novem­ber 2010 and 2011, putting home val­ues at roughly the same lev­els as 8 years ago. Don’t read too far into it, however.

The Case-Shiller Index, though widely-cited, remains widely-flawed.

As a buyer or seller , rely­ing on the Case-Shiller Index for mar­ket research can lead you to improper con­clu­sions. To under­stand the Case Shiller Index’s method­ol­ogy is to under­stand why.

First, the Case-Shiller Index draws its data from a very lim­ited geography.

Report Only Tracks 20 U.S. Cities

There are more than 3,100 munic­i­pal­i­ties nation­wide. The Case-Shiller Index tracks just 20 of them. And they’re not the 20 largest, either. Four of the Top 10 Most Pop­u­lous U.S. Cities are excluded (Hous­ton, Philadel­phia, San Anto­nio, San Jose) whereas Min­neapo­lis and Tampa are not.

Min­neapo­lis is the 48th largest city in the United States. Tampa is #55.

Next, when Case-Shiller Index gath­ers its data from its 20 cities, it only includes the home sale data of single-family, detached homes. This means that sales of con­do­mini­ums and multi-unit homes are specif­i­cally excluded from the index. There are some cities — Chicago and New York, for exam­ple — where con­do­minium sales rep­re­sent a large per­cent­age of the over­all market.

The Case-Shiller Index ignores that.

And, lastly, when the Case-Shiller Index is pub­lished, it’s pub­lished on a 60-day delay. Its data is not “cur­rent”, there­fore, and does lit­tle to tell buy­ers and sell­ers of the coun­try what’s hap­pen­ing in their home mar­kets right this minute. Instead, the Case-Shiller Index tells us how the hous­ing mar­ket looked two months ago.

If you’re active in the real estate mar­ket, either as a buyer or a seller, the Case-Shiller Index does you lit­tle good. For real-time data that action­able, speak to a real estate pro­fes­sional instead. It’s where you’ll find your best, most reli­able and rel­e­vant information.

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