so i dunno where you get: "I see OPs like this, and they suggest that something evil has happened recently, without saying that specifically."
Since its inception, the CPI has been comprehensively
revised on six occasions to implement updated samples and
weights, expanded coverage, and enhanced methodologies.
For example, the 1998 revision, the most recent one, introduced
more timely consumer spending weights; updated geographic
and housing samples; a revised item classification
structure; a new housing index estimation system; computer-assisted
data collection; and a new Telephone Point-of-Purchase
Survey.
BLS also has made important improvements
to the CPI beyond the major revision processes, an example
being the introduction of the geometric mean formula in January
1999.
Table 1, on the following pages, provides a chronology
of revisions and improvements to the CPI, and appendix
3 displays historical changes in base period,
population coverage, and other index characteristics.
http://www.bls.gov/opub/hom/homch17.htm
Example of change in the 1998 revisions:
- Extended the use of hedonic regression to estimate the value of items changing in quality = more use of the hedonic adjustment
There have been three 'comprehensive' & 2 non-comprehensive overhauls of the CPI since 1973.
= new reply since forum marked as read
