Its true, the Big Mac index was created to compare PPP, but it also inadvertently has historical data on Big Mac prices going back to the 80's.
It was this data, not the PPP data that was used for the comparison. It also appears that John Williams and I are basically in agreement.
Peter Schiff and Forbes both ran articles on this after my original article in March.
Author of Shades of Thomas Paine, a common sense blog with a Libertarian slant.
Also author of Stick it to the Man!