“Case-Shiller reports ____”, “RMLS reports ______”, etc. We are inundated with data but what does it mean? When a report refers to “Portland,” what does that mean? The answer isn’t the same from each source reporting. Case-Shiller reports “Portland” as these counties: Clackamas OR, Columbia OR, Multnomah OR, Washington OR, Yamhill OR, Clark WA, and Skamania WA according to their methodolgy report.
The S&P/Case-Shiller Home Price Indices began as a research project in the 1980’s when Karl E. Case and Robert J. Shiller began to construct a methodology to measure housing price movement.
I’m not going to attempt to summarize the methodolgy of computing the index- it takes them 40 pages in the report above! They do publish a two page factsheet which discusses the use of “sale pairs.” A specific address is tracked and each sale creates a data point. The pair is then weighted for the time between points, etc. The site reports 2692 sale pairs in Portland for the June reporting cycle (RMLS reports 1877 closed sales for June as an indicator that they are using different areas). Case-Shiller does not report on condos or new construction; residential single family only and excludes foreclosures. There is additional reading on the FAQ sheet from Standard and Poors.