National Association Of Purchasing Managers Index

The National Association of Purchasing Managers (NAPM) Index is a monthly index of U.S. manufacturing compiled by the Institute of Supply Management (ISM). Previously known as the National Association of Purchasing Management Index, the NAPM Index is derived from the institute’s “Report on Business” survey of purchasing and supply executives across the nation. Until January 2, 2002, ISM was known as the National Association of Purchasing Management (NAPM). ISM changed its name to reposition itself in the broader context of supply management. However, the content of the "Report on Business" has not changed in any way. The only change is that the report is now called the ISM Report on Business.

 
The National Association of Purchasing Managers (NAPM) Index is considered one of the most reliable leading indicators available to assess the near-term direction of the U.S. economy. Also known as the PMI Composite Index, an index reading above 50 percent indicates that the manufacturing sector is generally expanding, while a reading below 50 percent indicates contraction. The further the index is away from 50 percent, the greater the rate of change. The report for a specific month is released on the first business day of the following month. It has been issued without interruption since 1931, except for a four-year hiatus during World War II.

The NAPM Index – which is now known as the ISM Index – is derived from the “Report on Business” survey that encompasses 18 diverse sectors of the U.S. manufacturing economy. It is sent out to survey respondents in the first part of each month, with respondents asked to report changes in 10 specific business activities as compared to the previous month. These activities are new orders, production, employment, supplier deliveries, inventories, customers’ inventories, prices, backlog of orders, exports and imports.
 
For each business activity, survey respondents indicate whether it has increased, decreased or remained unchanged from the previous month. The data for each activity is used to compile a diffusion index, which is calculated by adding the percentage of respondents who report that the activity has increased with one-half of the percentage who report unchanged activity. For example, if 30 percent of respondents in a particular month report that production has increased, 45 percent report no change, and 25 percent report a decrease, the diffusion index for production would be 52.5 percent.