House price data has a clear seasonal pattern, and I think the headlines for this data should be the Seasonally Adjusted number.
The following graph shows the month-to-month change of the Case-Shiller Composite 10 index for both the NSA and SA data (annualized). Note that Case-Shiller uses a three-month moving average to smooth the data.
Click on graph for larger image in new window. The Blue line is the NSA data. There is a clear seasonal pattern for house prices.
The red line is the SA data as provided by Case-Shiller.
The seasonal adjustment appears pretty good in the '90s, however it appears insufficient now. Still the SA data is probably a better indicator than the NSA data - and to be consistent I've kept reporting the SA data.
The second graph compares the Case-Shiller Composite 10 SA index with the Stress Test scenarios from the Treasury (stress test data is estimated from quarterly forecasts).
NOTE: This is using the Seasonally Adjusted (SA) composite 10 series.
The Stress Test scenarios use the Composite 10 index and starts in December. Here are the numbers:Case-Shiller Composite 10 Index, November: 157.66
Stress Test Baseline Scenario, November: 140.86
Stress Test More Adverse Scenario, November: 128.54
This puts house prices 12% above the baseline scenario and 22% above the more adverse scenario.