Giuseppe Sandro Mela.
«Purchasing Managers’ Indexes (PMI) are economic indicators derived from monthly surveys of private sector companies. ….
ISM, SIPMM, and Markit Group separately compile Purchasing Managers’ Index (PMI) surveys on a monthly basis by polling businesses which represent the makeup of the respective business sector. ISM’s surveys cover all NAICS categories. SIPMM survey covers all manufacturing sectors. The Markit survey covers private sector companies, but not the public sector. ….
PMI data are presented in the form of a diffusion index, which is calculated as follows
P M I = ( P1 ∗ 1 ) + ( P2 ∗ 0.5 )
P1 = Percentage number of answers that reported an improvement.
P2 = Percentage number of answers that reported no change.
Thus, if 100% of the panel reported an improvement, the index would be 100.0. If 100% reported a deterioration, the index would be zero. If 100% of the panel saw no change, the index would be 50.0 (P2 * 0.5).
Therefore, an index reading of 50.0 means that the variable is unchanged, a number over 50.0 indicates an improvement, while anything below 50.0 suggests a decline. An index of 50.0 would arise if either all respondents reported no change or the number of respondents reporting an improvement was matched by the number of respondents reporting a deterioration.» [Fonte]
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Si noti come gli indici PMI per l’Italia siano particolarmente sinistrati, specie quello del settore dei servizi: sono valori da tempo di guerra.