A tale of two indexes: Which inflation metric should you trust?

Subscribe to enjoy similar stories.Kevin Warsh, President Donald Trump’s nominee for Fed chair, faced pointed questions Tuesday at his Senate Banking Committee confirmation hearing, with lawmakers zeroing in on his lack of investment disclosures, his stance on Fed independence and, of course, inflation.While the public watches the consumer price index (CPI) to follow inflation, the Federal Reserve spends its time tracking a different set of initials: PCE.The personal consumption expenditures price index, a monthly measure of the prices Americans pay for goods and services, is the Fed’s preferred gauge of inflation and a key input in its interest-rate decisions.Damjan Pfajfar, vice president in the research department at the Federal Reserve Bank of Cleveland, said the central bank prefers the PCE because it provides a “broader measure of inflation.” Speaking with Barron’s on April 17, he said PCE is a “more accurate reflection of what consumers are actually spending.”Compared with the CPI, which only includes urban consumers, the PCE also measures rural households and spending done on behalf of consumers, including employer-provided health insurance, Medicare and Medicaid. With monthly updating of its weightings—the relative importance of different sectors—the index also better reflects shifts in consumer behavior, such as substituting pricier options for lower-cost alternatives.

CPI weights are updated once a year.That’s great for the Fed, but why does it matter for investors? The simple answer is this: What matters to the Fed matters to investors. When PCE comes in hot, as it has over recent months, the central bank is more reluctant to lower interest rates.