報紙常常搞錯一些觀念，不足為奇，但是有時候研究報告，也會有同樣的狀況，以最近大家常常談論的製造業PMI來說好了，今天報紙就說製造業PMI大於50，代表景氣擴張，小於50，代表景氣衰退，通常我們說"景氣"，意旨總體經濟(通常以GDP表示)，正確應該說，製造業PMI大於50，代表製造業景氣(manufacturing economy)擴張，製造業PMI小於50，代表製造業景氣衰退，但不代表總體經濟衰退，根據美國ISM協會網站，製造業 PMI只要持續超過42.5，就代表經濟(overall economy)擴張，不需要到50，而9月的51.6年化之後，則代表 GDP是3.2%。經濟會不會衰退，是另一個議題，這裡只是說明，PMI<50，不代表經濟衰退。。
Manufacturing continued its growth in September as the PMI registered 51.6 percent, an increase of 1 percentage point when compared to August's reading of 50.6 percent. A reading above 50 percent indicates that the manufacturing economy is generally expanding; below 50 percent indicates that it is generally contracting.
A PMI in excess of 42.5 percent, over a period of time, generally indicates an expansion of the overall economy. Therefore, the PMI indicates growth for the 28th consecutive month in the overall economy, as well as expansion in the manufacturing sector for the 26th consecutive month. Holcomb stated, "The past relationship between the PMI and the overall economy indicates that the average PMI for January through September (56.2 percent) corresponds to a 4.8 percent increase in real gross domestic product (GDP). In addition, if the PMI for September (51.6 percent) is annualized, it corresponds to a 3.2 percent increase in real GDP annually."