Primer: Core And Median CPI Justification — Brian Romanchuk

One practice of economists that draws a lot of complaints is the use of subsets of the consumer price indices. Most commonly it is core CPI – excluding food and energy – although there are fancier measures like median CPI (which I describe below). Meanwhile, if a component of the CPI rises a lot in a month, commentary will often state things like “if we exclude {whatever had a price spike}, then CPI increased by only 0.2% on the month, instead of 0.5%.” (As should be expected, complaints are only about excluding items that rose quickly, everybody is happy to throw away the effects of items that fall rapidly in price.)...

Bond Economics
Primer: Core And Median CPI Justification
Brian Romanchuk