Excerpt: “Originally, the CPI was determined by comparing the price of a fixed basket of goods and services spanning two different periods. In this case, the CPI was a cost of goods index (COGI). However, over time, the U.S. Congress embraced the view that the CPI should reflect changes in the cost to maintain a constant standard of living. Consequently, the CPI has evolved into a cost of living index (COLI). ... Over the years, the methodology used to calculate the CPI has undergone numerous revisions. According to the BLS, the changes removed biases that caused the CPI to overstate the inflation rate. The new methodology takes into account changes in the quality of goods and substitution. Substitution, the change in purchases by consumers in response to price changes, changes the relative weighting of the goods in the basket. The overall result tends to be a lower CPI. However, critics view the methodological changes and the switch from a COGI to a COLI as a purposeful manipulation that allows the U.S. government to report a lower CPI.”.
https://www.investopedia.com/articles/07/consumerpriceindex.aspA few take aways:
- The methodology for computing CPI has undergone several changes over the
years So, it’s not the same yardstick today as it was 30, 40 or 50
years ago. Looking at long term historical CPI numbers as some type of
norm is tantamount to comparing apples to oranges (or at least mixing them together)..
- These changes were to an extent politically inspired.
- CPI purports to take into account the
increased value of the products consumers purchase. So, if you choose to drive a stick shift car with an AM radio and roll-down windows and without power steering, seat-belts or side view mirrors, than the price of new cars has increased by only 2-3% annually. (Good luck finding one.) You could also hue to that government figure by switching to B&W TV and sticking an antenna on your roof instead of enjoying cable. And if you could still find one in a box somewhere, buying a “new” Vic-20 home computer or maybe an Apple II E would allow you to fully appreciate that 2.9% inflation rate. Finally, (at great risk of being redundant), if you can find a physician willing to provide only the level of health care (including prescription medications) you would have received 50
years ago, than your health care costs may have increased by that 2-3% number.
- It would be nearly impossible to measure the
change in the value of some products. Take air travel for instance. How in jiggers do you calculate the real cost difference when the airlines keep tacking on fees for things like checking a bag, using the overhead storage compartment or selecting a window seat? But if you could, you’d still have to figure out how to account for the
diminished value stemming from the discontinuance of meals on flights (once standard), non-refundable tickets and smaller more uncomfortable seats.
- CPI doesn’t consider the increasing need for medical care as the population ages. So CPI for those of us 70+ may be a bit different (I suspect somewhat higher) than for a much younger individual.
I don’t know whether those numbers Catch quoted included the effect of compounding. But suspect not. When running a 3% inflation rate through a compounding calculator I get a 15.93% cost increase over 5
years. Inflation looks a bit more onerous when viewed over longer periods.