The Personal Consumption Expenditures price index. Broader than CPI — covers all goods and services consumed by Americans, not just urban consumers.
PCE is more comprehensive than CPI and adjusts for substitution effects. The Fed officially targets PCE inflation at 2%, not CPI.
Generally runs 0.3-0.5% below CPI. The trend direction matters more than the absolute level. Falling PCE gives the Fed room to cut.