Occupation-Specific Population Models: Population and Dynastic Cycles

As Lee (1987) pointed out, vital rates of the human population are often determined by forces such as culture, institutions, technology, and individual rationality, forces that have little to do with density pressure or prior growth. Perhaps most people also expect “rational” human practice to weaken the biological responses of both fertility and mortality to density pressure, while strengthening the nonbiological response through institutional regulations. But can human institutional designs and rational responses really reduce the impact of natural checks? As we study the pattern of population dynamics in ancient China, we can provide some viewpoints different from the general opinion. The long-term relationship between human institutional designs and natural checks is discussed in chapter 14. The books by Ho (1959) and Chao and Hsieh (1988; hereinafter C&H) contain the most thorough research on the history of Chinese population. The data summarized in C&H have presented us with a time-population diagram, shown in figure 9.1. From this figure, as well as other related literature, the following “stylized facts” of population dynamics in Chinese history can be summarized: 1. Population declines often coincided with dynasty changes (C&H; Ho, 1959). 2. Population declines were often drastic in a rather short period of time. 3. Natural checks such as famine and epidemics did not independently reduce the population surplus (Ho, 1959); rather, population declines were often the direct and indirect results of internecine wars. 4. There are obvious peaks and troughs in the population data, but no regular cyclical patterns (C&H). The fact that no serious population decline appears to have been independently due to famines and epidemics seems to suggest a weak pattern of density-dependency for ancient Chinese populations, a pattern consistent with the observation of Lee mentioned in the beginning of this chapter. However, as noted by many historians (see, e.g., Ho, 1959, and C&H 1988), the frequent clashes between soldiers and rebellious peasants in Chinese history were often initiated by famine or density pressure. As such, the originally weak natural checks on population were often magnified by war, and such magnified “institutional checks” caused very drastic population changes.