History of CPI Numbers being Suppressed
Since 1975 when the government first started making COLA adjustments for Social Security benefits, the government has had an incentive to keep inflation low. With lower inflation they pay out less money to Social Security recipients. One way to do that is by adjusting the CPI calculation. There were major adjustments in 1980 and 1990 that reduced CPI. Today if inflation were calculated like 1980, it would be up 9% compared to the reported 1.3%. If CPI were calculated like 1990, the rate today would be 5%. There is talk of moving the COLA adjustments to chained-linked CPI, as tax brackets were changed to the chain-linked CPI in 2017.