Interpreting Indian economic data is difficult even at the best of times. The challenge intensifies when two indicators that ostensibly track similar activity send sharply diverging signals, as in the case of India’s manufacturing Purchasing Managers’ Index and the Index of Industrial Production.In July, the HSBC Flash India Manufacturing PMI surged to 59.2, a nearly 17-and-a-half-year high, from 58.4 in June. According to S&P Global, which compiles the data, the reading indicated a “robust improvement in the health of the manufacturing industry”. The last time the PMI was this high was in February 2008, when it touched 59.5.