1. Clearly the phenomenon, when it occurred, was multi-causal, and it was not the same everywhere. For example, it is explicitly recorded that women did not take part in the heavier tasks of farming in Zunhua, in the north-east, even at the end of late-imperial times, though they did weed, pick cotton and beans and carry food to the workers in the fields.
2. Karlgren , Odes, p. 190 (Mian).
3. Discussed in Elvin, “Three thousand years,” pp. 17–18.