&gt; The phrase &quot;during CPI calculation&quot; should be the key to understanding here. CPI tells you how much prices have gone up or down generally, by just sending a bunch of secret-shoppers around to measure a bunch of prices.<p>CPI tells you how much prices have changed, it doesn&#x27;t explain the source of the changes (and, particularly relevantly, it doesn&#x27;t measure isolate effects of changes in the supply of dollars chasing the good -- that would be attributed to the degree of elasticity -- vs. other influences on the price of an item.)