Bartek Sadowski | Bloomberg | Getty Images
Workers assemble an Opel Astra automobile near a supply of glass panels at the Opel automobile plant in Gliwice, Poland, on Monday, March 6, 2017.
Despite these criticisms, there are others who defend the data. Claus Vistesen, chief Eurozone economist at Pantheon Macroeconomics, said PMI data tends to lead industrial production data, and that plotting out upturns in PMI is consistently associated with upturns in industrial production growth.
“What often happens is that the PMI increases, which the market reacts to. Production growth then increases, but part of this response comes via upward revisions to previous data,” Vistesen told CNBC via email.
“This is of little help to markets which tend to look forward, but it shows that the PMIs are a useful short leading/real time indicator.”
Vistesen added that PMI data are a useful short leading indicator for real monthly activity, at least in the Eurozone.
Follow CNBC International on Twitter and Facebook.