Official name: Federal Reserve Statistical Release G.17
What exactly? A measure of the change in the production of the nation's factories, mines and utilities. Also includes a measure of their industrial capacity and how much of it is being used (commonly known as capacity utilization).
Source: Federal Reserve
Released when? Around the 15th of the month at 9:15 a.m. Eastern. Data for prior month.
Market importance: Much. Frequently moves markets. Timely. Considered a key factory-sector gauge. Capacity utilization considered a telling inflation indicator.
Other notes: (a) The level of industrial production divided by the level of industrial capacity equals the capacity utilization rate. (b) The headline numbers are the percent change in production from the prior month and the capacity utilization rate. We also graph the year-on-year change in both production and capacity, alongside capacity utilization, to illustrate the relationship between the three.