How do prices change over time?
Prices tend to go up, especially over long periods. But some prices can increase much faster than others and some can even decrease. Over the past 40 years or so, price changes for goods have tended to be lower than price changes for services.
Our FRED graph above uses data from the consumer price index release table to track price changes for some specific goods. The average CPI, shown by the solid blue line, is noticeably higher than the values for all the specific goods listed in the graph.
Our FRED graph below tracks price changes for some specific services. The average CPI, shown by the same solid blue line, is noticeably lower than the values for all the services listed in the graph.
Why are price changes for goods below average?
Increases in quality and productivity have allowed for slower increases in the prices of many goods and even some actual price declines.
The quality of cars has improved considerably. These enhancements have to be factored-out to get a genuine apples-to-apples price reading that can be compared over time.
For example: If you pay $35,000 for a car today and 8 years ago you paid $25,000, then the difference in purchase price is $10,000. But consider this: You’re also getting the most modern features with your new car, such as automatic emergency braking and keyless entry with biometric access. Those features weren’t available when you bought your previous car. So, because you’re getting much greater value with this purchase, the adjusted CPI price increase would be much less than $10,000.
The same applies to computer equipment, which wasn’t even a consumer good in the early 1980s.
Productivity in manufacturing has also improved considerably. Apparel, toys, and car parts, for example, can be produced much more efficiently or in lower-cost locations than before. As engineers find more efficient ways of making things, those things become (relatively) cheaper.
Why are price changes for services above average?
It is much more difficult to improve productivity for services than it is for goods, so services have gotten much more expensive. Consider education and medical care, for example. You cannot successfully increase classroom size beyond some point, and you cannot put more patients in a single hospital bed. Another example is the barber: Technology improvements in hair cutting have been very limited, and barbers still serve roughly the same number of customers each day as they did 40 years ago.
Of course, the rise of artificial intelligence may create new trends for some services. A topic for another day.
One more thing to know about the CPI
A good that has actually gotten much more expensive over time is tobacco products. These products have had increasingly higher taxation for several decades, with the intent to reduce their consumption. Helpfully, the CPI accounts for taxes when it calculates price changes.
How these graphs were created: Start from the CPI release table noted above, which you can find in the notes for the CPI graph or any of its components in FRED. Check the series you want displayed. Click on “Add to graph.” Change the start year to 1983.
Suggested by Christian Zimmermann.