Why has calculation changed over time in the U.S.?

Consumer prices are increasing at the fastest clip in about 40 years, climbing 8.3% in April compared with a year earlier.

As popular anger about the rising costs mounts, a chorus of critics has been arguing that the sky-high inflation figure is actually being undercounted.

In YouTube videos, on conservative talk shows and in posts by financial analysts, the critics argue that over the past several decades economists have tweaked one of the government's standard measures of inflation, the consumer price index, in ways that understate how quickly prices are rising. Those lower inflation figures give the government some economic breathing room, they claim, saving money on expenses like Social Security.

“The bottom line is these are not accurate numbers,” Tucker Carlson, the Fox News host, said during a segment on inflation late last year. He added, “Do the math and you will see that the actual number, the rise in inflation, is not even close to the 7% that Washington is claiming.”

But experts on inflation say the changes to calculations over the years have made the reported rate a more accurate snapshot of how much prices are rising for shoppers. The rate under a different methodology might be higher, they say, but the effect would be small, and the alternative number would do a poorer job of reflecting the costs consumers were grappling with. Inflation affects different people differently, but that does not mean that the overall numbers are incorrect.

“You have to understand the concept: What are people currently paying for consumption?” said Alan Detmeister, who was formerly head of the prices and wages section at the Federal Reserve and is now at the bank UBS. “It is trying to get at outof-pocket expenses.”

Here are two major changes made to inflation since the 1980s