SINGAPORE — The gap between the official China factory index and the one produced by HSBC reached its widest point in two years in March, raising an important question: Which has a better handle on the country’s economic growth?

The encouraging news for those who believe that the Chinese economy will have a soft landing is that the more bullish official purchasing managers’ index appears to be more closely correlated with economic conditions and a better predictor of things to come.

This suggests that although China’s growth in demand for commodities is certainly not going to be anywhere near double digits, it will hold up and provide a floor to prices. But that does not suggest there is little worth in the HSBC measure, as the two indexes capture different parts of the vast economy and both provide valuable insights.

The official P.M.I. rose to an 11-month high of 53.1 in March from 51 in February, topping analyst forecasts of 50.5. A reading above 50 signals expansion.