What Is the Industrial Production Index (IPI)? How It Measures Output
The Industrial Production Index (IPI) is a monthly economic indicator that measures real output in the industrial sector—primarily manufacturing, mining (including oil and gas field drilling services), and electric and gas utilities—relative to a base year. It tracks production levels, estimated sustainable production capacity, and capacity utilization (the ratio of actual output to capacity).
Who publishes it and frequency
- The Federal Reserve Board (FRB) publishes the IPI each month, with routine revisions released annually.
- Data are available in seasonally adjusted and unadjusted formats.
What the IPI measures
- Production: actual physical or inflation-adjusted measures of output (e.g., tons produced, adjusted sales, hours worked).
- Capacity: an estimate of the level of production that could be sustainably maintained.
- Capacity utilization: actual production divided by capacity, indicating how fully resources are being used.
How the index is calculated
- Index levels are expressed relative to a base year (currently 2012), so values reflect percentage changes from that base rather than absolute volumes.
- The FRB aggregates varied source data from government agencies and industry associations and combines them using the Fisher-ideal index formula.
Detail and sub-indices
- The IPI includes a composite index for the overall industrial sector and dozens of detailed sub-indices for specific industries (for example, residential gas sales, audio/video equipment, paper, steel products, and many others). These sub-indices help managers and sector investors monitor trends at a granular level.
How to interpret capacity utilization
- Low capacity utilization (overcapacity) signals weak demand and may point to the need for fiscal or monetary stimulus; it can also foreshadow industry downturns.
- High capacity utilization can indicate an overheating economy, increasing the risk of price pressures and asset bubbles; it may prompt tighter policy (e.g., higher interest rates) or eventual cyclical slowdown.
- For investors and policymakers, capacity utilization provides insight into demand strength, inflationary pressure, and potential policy responses.
How IPI differs from GDP
- IPI focuses strictly on industrial output and does not include value added in the retail or services sectors.
- GDP measures total economic output at market prices and therefore captures broader value added across the economy.
- The industrial sector accounts for a shrinking share of total economic activity (under roughly one-fifth of GDP), so IPI captures an important but limited portion of overall economic performance.
Data history and uses
- IPI time series extend back many decades, making the index useful for historical analysis of industrial cycles.
- Uses:
- Economists and macro investors use the composite IPI to gauge industrial-sector contributions to economic growth.
- Managers and industry investors use sub-index data for operational and investment decisions within specific lines of business.
Key takeaways
- The IPI is a monthly FRB-published index of industrial production, capacity, and utilization relative to a base year.
- It is calculated from a mix of physical output, adjusted sales, and labor measures, aggregated with the Fisher-ideal formula.
- Capacity utilization from the IPI is a timely indicator of demand strength and inflationary pressure.
- IPI complements GDP but focuses exclusively on the industrial component of the economy and detailed industry-level output.