Today S&P released the Q2 figures for its S&P/Case-Shiller® Home Price Indices. Not entirely surprisingly, the numbers are suggesting that the average price for single-family house in the top 20 metro areas is down 3.2% from a year ago.

Out of the 20 metro areas tracked by the index, 14 reported a year-over-year decline and Detriot is leading the board with a tumble of 11%. Some other cities, however, are still maintaining single-digit appreciations, including 7.9% in Seattle and 6.9% in Charlotte.

Here are the individual readings and year-over-year changes of each of the 20 areas:

And here comes some pessimistic remarks in a WSJ article reporting the same data set:

"These pricing pressures have not been seen in post-World War II history," said economist Brian Bethune at Global Insight. "It's very difficult for the markets to be able to deal with that kind of stress."

Mr. Bethune noted that today's price declines are worse than those during the housing bust of 1990-91 that preceded a national recession. "The housing market is definitely a leading indicator of a potentially more serious downward moment in the economy," he said.

Since the recent turmoil in the credit market happened after the reporting period of this release, we couldn't yet assess the impact to the home price. But most likely, things will get worse before they get better. Not entirely a bad news for me (given I don't own a property now), although housing price in Seattle, where I bought and sold a house in the last five years, is still strong.

By the way, if you are confused of the different home price indices, Forbes has a good piece discussing the differences:

On Monday, the National Association of Realtors reported its first year-long slide in home prices. The NAR said the median price of homes sold in July was down 0.6 pct from July of 2006. It was the first time the national median price has fallen 12 months in a row since the NAR's price records began in 1968.

And on Thursday, federal housing records are expected to show their first median price decline since they began in 1950. Economists are predicting a 1-2 pct drop for the quarterly index released by the Office of Federal Housing Enterprise Oversight -- Fannie Mae's and Freddie Mac's regulator.

Each of the indexes has its deficiencies. S&P's Case-Shiller indexes capture prices at repeat sales or refinancings on the same homes. That means they are not biased by a shift in the composition of sales -- toward cheaper or more expensive homes -- which can happen in the Realtors' reported median price. However, it tends to be over-weighted in real estate bubble regions such as Los Angeles and Miami. The OFHEO median captures only 'conforming' mortgages of 417,000 usd or less and leaves out so-called jumbos.

Despite the deficiencies, economists say the home price reports are all describing the same picture -- one that puts off potential buyers. People don't want to borrow money to finance what could be a depreciating asset.