ISM Manufacturing Index Shows Rate of Change, Not Levels

Come on folks, know what you are reporting. A NYT headline telling readers, "U.S. manufacturing gauge falls to June 2009 level," makes no sense. The index, the Institute for Supply Management index of manufacturing activity, shows changes in manufacturing, not levels. This means that the comparison to June 2009 is at best misleading.

The June measure came after many months of severe contraction that was gradually coming to an end. The April reading follows more than three years where the inde...