Crafting a reliable leading indicator is a tricky business in the world’s most mature economies, with analysts using a cocktail of different data points to try to get ahead of the curve in forecasting growth. In a developing nation, especially one that is growing and changing as quickly as China, the task is much harder because there are few consistent reference points to compare.

Yet in recent years, several leading indicators for China have garnered attention after doing a good job of predicting the economy’s slowdown at the end of 2008 and its subsequent recovery.