Posted Friday, April 30 2010
If you were curious how the Census ACS Median Value for Owner-Occupied Housing Units measure compares to an HPI measure like the Case-Shiller index, the chart below is for you.
Census ACS Median Home Prices vs. Case-Shiller
The answer is: not well. ACS home prices are derived from surveys (pdf) that ask how much a homeowner thinks their house would sell for. Clearly this is not as sophisticated as the repeat sales methodology of Case-Shiller and the FHFA which yield a price index not an actual price. Real prices are nicer to work with than indices, but not at the expense of accuracy. I wanted to compare the two to see if there was any way I could have confidence in the ACS number. I don't think there is, at least not at the national level.