The plunge in U.S. home values continues. Home prices in the United States in 20 cities declined at the fastest pace ever, as foreclosures increased and banks sought to unload homes by selling at cut-rate prices.

Home prices in a 20-city sample plunged a record 17.4% in September, on a year-over-year basis in, according to the S&P / Case-Shiller U.S. National Home Price survey (pdf). The index has fallen every month since January 2007. Home prices fell 16.6% in August, on a year-over-year basis.

Further, prices in a 10-city survey also plummeted a record, 18.6%, on a year-over-year basis.

Economists surveyed by Bloomberg News had expected home prices in the Case-Shiller survey to decline 16.0-17.2% in September on a year-over-year basis.

The areas with the largest annual percentage declines were: Phoenix, -31-9%, Las Vegas, -31.3%, San Francisco, -29.5%, Miami, 28.4%, Los Angeles, -27.6%, and San Diego, -26.3%.

The decline in U.S. home values continues. Home prices in 20 top U.S. cities declined at the fastest pace ever, on a year-over-year basis, as foreclosures increased and banks sought to unload homes by selling at cut-rate prices.

Home prices in a 20-city sample plunged 16.6% in August, on a year-over-year basis in, according to the S&P / Case-Shiller U.S. National Home Price survey (pdf). The index has fallen every month since January 2007. Further, prices in a 10-city survey plummeted a record 17.7% in August on a year-over-year basis.

Economists surveyed by Bloomberg News had expected home prices in the 20-city Case-Shiller index to decline 15.9-17.1% in August on a year-over-year basis.

Large price declines in western U.S.

The areas with the largest annual percentage declines were: Phoenix, -30-7%, Las Vegas, -30.6%, Miami, 28.1%, San Francisco, -27.3%, Los Angeles, -26.7%, San Diego, -25.8%.

Not one Top 20 metro area experienced a year-over-year increase in home values as of August and only two cities saw an increase in home prices in the month of August: Cleveland, 1.1% and Boston, 0.2%. Prices in Denver were flat in August.

The U.S. housing sector has registered another ignominious statistic. Home prices in a 20-city sample plunged 14.4% in March 2008 (PDF), on a year-over-year basis, according to the S&P / Case-Shiller U.S. National Home Price survey released Tuesday. Meanwhile, prices in a 10-city survey plummeted 15.3%.

It was the largest decline in the survey's 20-year history, Case-Shiller said.

Economists surveyed by Bloomberg News had expected home prices in the Case-Shiller 20-city survey to decline 14.2% in March 2008 on a year-over-year basis.

The areas with the largest percentage declines were: Las Vegas, -25.9%; Miami, -24.6%, and Phoenix, -23.0%. Only one city in the survey -- Charlotte, N.C. -- appreciated, with prices there rising just a scant 0.8%.

Percentage price changes in other major U.S. cities were as follows: New York, -7.4%, Los Angeles, -21.7%, Chicago, -10.0%, Boston, -5.9%, San Francisco, -20.2%, Washington, D.C., -14.7%, Miami, -24.6%, and Seattle, -4.4%.

Economic Analysis: Another horrible U.S. housing sector statistic, and the sector remains in deep recession. Economists differ regarding whether the U.S. housing sector has bottomed: some see a housing recovery as early as Q4 2008, while others say it won't start until mid-2009. In either event, it's going to be a while before new home builders can resume typical building schedules and get out there and make some money -- a fact that suggests U.S. home prices are likely to continue to decline for at least the next two quarters, and probably longer.