Consumer Price Index
A monthly measure of the average change in prices paid by urban consumers for a basket of goods and services.
The Bureau of Labor Statistics publishes the CPI monthly. Two figures are commonly quoted from it: the month-over-month change, and the twelve-month change, which is what people usually mean by “inflation is running at X percent”.
Two cautions when reading it. “Core” CPI excludes food and energy — not because those do not matter, but because they are volatile enough to obscure the trend. And the Federal Reserve’s 2% target is defined on a different index, the price index for personal consumption expenditures, which weights spending differently and typically runs a little below CPI.
The headline inflation number in most coverage. It is not the index the Fed targets — that is the PCE price index.