One of the most commonly accepted notions in studies of Chinese history is that farm labour productivity declined in the late Imperial period.

Even for those who reject the stereotype cliches of a ‘stagnant and unchangeable China', who see economic changes in late Imperial China resembling those of early modern western Europe, the fundamental picture has changed little.⁴ Jiangnan has drawn the most attention, partly because of its special position in Chinese economic history.

If one examines the conventional story more closely, however, it becomes clear that it is based upon several frequently made assertions. First, it is thought that Jiangnan witnessed a rapid population growth during the eighteenth and early nineteenth centuries, even though it had been the most populated area of China well before the seventeenth century. Second, because almost all arable land had been opened up as early as the late fourteenth century, land increased little, if not at all, in Jiangnan during the following centuries. Consequently, the acreage per capita of cultivated land shrank rapidly. Third, yields per mU of the major crops are believed to have reached a ceiling in the context of traditional technology by the late sixteenth century or even earlier. Since no major technological breakthroughs appeared during the following centuries, there was a centuries-long stagnation of yields per mu of major crops. When yields were constant, increased labour inputs would make the returns on labour diminish at an accelerating rate. These arguments lead to an unavoidable and indisputable conclusion; farm labour productivity would fall. It is on the basis of these claims that some celebrated theories, such as Mark Elvin's ‘high-level equilibrium trap' and Philip Huang's ‘involutionary growth', have been put forth. Unfortunately, the evidence to support these claims is inadequate for pre- 1850 Jiangnan history. Therefore, any theory based on these arguments is quite likely to be discredited since they rest on fragile ground.

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