PMAC - Purchasing Management Association of Chicago. Copyright Kingsbury International, Ltd. 2008, Reprinted with permission The NAPM-C Business Survey The monthly survey of business activities by the National Association of Purchasing Management - Chicago (NAPM-C) provides a unique and timely measure of general economic activity. The market-moving series Prices Paid attracts national attention, while the activity. The Business Barometer provides a timely measure of USA economic pervasiveness of economic trends can be gauged from the results of this survey of around 200 selected members of the NAPM-C membership (response rate about 50%). The survey is released on the last working day of each month at 9am USA Central Time.