I’ve heard that the consumer price index is not the best measure to compare the cost of a widget as purchased by a working or middle class family as the CPI is prone to manipulation by people that have an interest in keeping it artificially low. The context of the question is that it seems like books were more luxury items back in the 1950s than today; series books like the Hardy Boys were deliberately kept cheap, generally $1, but there’s a scene from Beezus and Ramon (1955) where it’s mentioned a children’s hardcover picture book from the library that Ramona ruined that the family had to pay for costs $2.50.
Maybe a related question, were books more luxury items then; it seems now every family has at least a couple of bookcases full of books. Beezus mentions that it was “a lot of money” but would that just be from a kid’s perspective or would it be expensive from an adults perspective too?
An article with a look at what CPI was and what it is along with some of the debate.
Originally it was a relatively simple basket of goods approach. The prices of certain amount of goods were tracked over time. That’s probably what is most useful for the kind of comparison you want. It doesn’t really get after inflation in a very specific chunk of the market like book prices but the aggregate is probably most useful.
It changed into something that’s more a cost of living change indicator to maintain a certain standard of living. That methodology attempts to take into account changes in quality of goods and substitution of goods. That’s what much of our government policy uses it for, after all. Because there’s more chance to influence the results given the greater tweaking some argue that is where the manipulation can happen. Since it can save the government huge quantities in cost of living increases and make GDP growth look better there’s certainly an argument that there’s an incentive to manipulate for some.
The article does bring up two economists who maintain separate measures. One uses the original basket of goods approach. That might be best suited for what you are after. I’m not sure if you can dig out what you want without a subscription to his site without digging more. There’s another interesting take by an economist that doesn’t think the CPI is manipulated. He just thinks it’s a lagging indicator that measures past inflation. He argues for a fixed basket of metals as a more relevant of current inflation. That’s probably less the approach you want since the lag isn’t hugely relevant for a comparison across decades.
There is no actual reason to think that’s true. Pretty much every govt would spend less on benefits, and also debt (inflation adjusted bonds which are now a non-negligible % of US debt, higher for some other countries) if inflation is lower. That doesn’t mean the figures are ‘manipulated’. And ‘here in the UK it seems pretty accurate to me’ is IMO simply a difference in attitude, not any difference in underlying facts. The UK govt has basically the same ‘motive’ to ‘manipulate’ inflation figures as US or other ones. I don’t think the UK or US govts do so.
The inflation methodology is not a secret. Depending what you think it should capture there’s room for some debate about it but that’s different from claiming it’s ‘manipulated’ based on ‘who benefits’ type argument but no actual evidence.
Anyway whatever the most subjectively ‘correct’ measure is, you can’t expect it to apply uniformly over all goods. Substitution and improvement in goods (including not previously existing goods) are both real factors in the economy. An index ignoring both those both factors entirely over long periods is surely misleading. But by the same token you can’t expect any variation (there are several) of official CPI, or the PCE Deflator (which is what the Fed targets when it wants ‘inflation’ to not be less than ~2%, and which tends to come out some 0.1%'s per year less than CPI) to come out spot on for the retail prices of each type of good over periods of decades. Inflation is the general change in the price level, there’s no way it will be the same for all goods over long periods.
For relatively recent times, I second this - follow minimum wage. Here in Canada, the minimum wage was IIRC 90 cents/hour in 1968 before inflation went hg-wild, and today it’s a little over $10 for most places. So a little over 10x since then. Of course, a pack of cigarettes was 35 cents then and comics were 10 cents, etc. McDonalds hamburgers were 25 cents.
Some things are not comparable - clothing was generally made locally 50 or 60 years ago (and tariffs stopped foreign imports) whereas today our designer clothes with the expensive labels are put together by foreign workers lucky to make today the $1/hr that was minimum wage here back then.
Cigarettes in Canada are taxed out the wazoo so not an apt comparison, even if I knew what a pack goes for.
Comic books were cheap crap for kids - now they are artsy collector’s items. Not the same.
OTOH, a plain loaf of bread was about 22 cents back then (it was big news when it went up a cent) and today, something similar is about $2… so spot on.
An imperial gallon of gas was just over 42 cents, now depending on where you are in the country, 4 litres is $4 to $5.50.
Some things are tech-influenced or government policy determined. Long distance calls and air travel come to mind. Newspapers used to be a dime, but now are (I think, I don’t buy them) over $1, due to declining ad revenue so they have to charge more, for a less substantial product, despite technological advances.
Wages, measured in “real” terms, vary in time and space so when comparing prices you must ask: Price relative to average wage? or Price relative to a coin or commodity? At this page you can type in a beginning and ending year and click to see a table with Retail Price Index, Average Nominal Earnings, and Average Real Earnings. That final column (#3) is redundant: it’s 100*#2/#1.