It measures prices compared with those in January 2000 and creates a three-month moving average.

WSJ: US home prices rise 10.9 pct., most since 2006

Its three-month moving average, considered a recession indicator, fell from -0.26 in July to -0.47 in August.

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Its closely watched three-month moving average is now at -0.4, just fractionally above the -0.7 level that has marked the beginning of all seven recessions that have taken place since 1970.

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