The CPI chart on the home page [as reprinted above] reflects our estimate of inflation for today as if it were calculated the same way it was in 1990. The CPI on the Alternate Data Series tab here [the chart above], reflects the CPI as if it were calculated using the methodologies in place in 1980. Further background on the Alternate CPI and Ongoing M3 series is available in the Archives in the August 2006 SGS newsletter.
