Changes in how the rate is computed occurred in 1983 and again in 1998; the core rate obscures the real impact of price changes.
Excluding food and fuel costs from the inflation rate and calling it the 'core inflation rate' has hidden the real prices changes; it hasn't hidden the impact of those price changes. Folks still buy food and fuel.
Here's a site that 'splains inflation, core inflation, pre-1983 and pre-1998 inflation and the misrepresentations (euphemistically speaking!) we are being fed:
inflation info site
Anyone who mentions the effectiveness of our economy as a function of our low core inflation without mentioning that food and fuel are excluded from the reported rate is an obfuscater! Those who compare rates from, e.g., pre-1983, with those reported today are comparing apples and oranges. If they are doing so knowingly then they are perpetrating a fraud.
By the way, has anyone seen any reports of the core rate recently? I would tend to doubt it as, given the recent increases in the costs of food and fuel, the prestidigitation would become obvious. It would be silly to report that core inflation has held steady at 2.3 percent annually while the cost of eggs, milk, butter and hamburger has increased an average of 20% over the last two months (these are not actual egg, butter and milk price price percentage increases but are used for example only).