The Federal Reserve's monthly index of industrial production and the related capacity indexes and capacity utilization rates cover manufacturing, mining, and electric and gas utilities. The industrial sector, together with construction, accounts for the bulk of the variation in national output over the course of the business cycle. The production index measures real output and is expressed as a percentage of real output in a base year, currently 2012. The capacity index, which is an estimate of sustainable potential output, is also expressed as a percentage of actual output in 2012. The rate of capacity utilization equals the seasonally adjusted output index expressed as a percentage of the related capacity index.
The index of industrial production is available nationally by market and industry groupings. The major groupings are comprised of final products (such as consumer goods, business equipment and construction supplies), intermediate products and materials. The industry groupings are manufacturing (further subdivided into durable and nondurable goods), mining and utilities. The capacity utilization rate -- reflecting the resource utilization of the nation's output facilities -- is available for the same market and industry groupings.
Industrial production was also revised to NAICS (North American Industry Classification System) in the early 2000s. Unlike other economic series that lost much historical data prior to 1992, the Federal Reserve Board was able to reconstruct historical data that go back more than 30 years.