May’s headline print for the CPI-U came in above expectations at 1.0 percent month-over-month (SA). This post reviews how May’s official prints compared to the real-time data, and generally followed with a one- to two-month lag.
Then, as we use the real-time data to peel the onion on the BLS’s sample and processes, we discuss how this release revealed important differences in the effective look-back of the Airfares vs. the Used Vehicles CPI-U’s. While the real-time Airfares CPI requires a 60-day look-back to match the CPI-U, as discussed in an earlier post, it turns out that Used Vehicles, by contrast, require a 30-day look-back. This suggests to us that flights that originate from different cities are in fact distinct products, while used cars are comparatively homogeneous goods that price more uniformly across geographic markets.