Here is a short excerpt from a recent blog posting by Bill Gross of Pimco, the world's largest bond holder:
The U.S. seems to differ from the rest of the world in how it computes its inflation rate in three primary ways: 1) hedonic quality adjustments, 2) calculations of housing costs via owners' equivalent rent, and 3) geometric weighting/product substitution. The changes in all three areas have favored lower U.S. inflation and have taken place over the past 25 years, the first occurring in 1983 with the BLS decision to modify the cost of housing. It was claimed that a measure based on what an owner might get for renting his house would more accurately reflect the real world – a dubious assumption belied by the experience of the past 10 years during which the average cost of homes has appreciated at 3x the annual pace of the substituted owners' equivalent rent (OER), and which would have raised the total CPI by approximately 1% annually if the switch had not been made.
In the 1990s the U.S. CPI was subjected to three additional changes that have not been adopted to the same degree (or at all) by other countries, each of which resulted in downward adjustments to our annual inflation rate. Product substitution and geometric weighting both presumed that more expensive goods and services would be used less and substituted with their less costly alternatives: more hamburger/less filet mignon when beef prices were rising, for example. In turn, hedonic quality adjustments accelerated in the late 1990s paving the way for huge price declines in the cost of computers and other durables. As your new model MAC or PC was going up in price by a hundred bucks or so, it was actually going down according to CPI calculations because it was twice as powerful. Hmmmmm? Bet your wallet didn't really feel as good as the BLS did.
Fooling With Inflation
