Temporal Changes in the Causal Mechanism of Demographic Responses

In the previous sub-sections, we found that there were significant temporal differentials in demographic responses to short-term economic stress. In order to directly examine whether there were any changes over time in the causal mechanisms of these demographic responses, we further conducted the discrete-time event-history analyses of the effects of rice price fluctuations on mortality, marital fertility, first marriage, and out-migration by dividing the entire period under consideration (1716-1870) into two sub-periods: the eighteenth century (1716-99) and the nineteenth century (1800-70).

In short, these separate analyses, divided into sub-periods, showed significant changes in the nature of the effects of rice price variations and household landholding only on first marriage, while there were no notable changes in their effects on the remaining three demographic outcomes, that is, mortality, marital fertility,

and out-migration (data not shown). Specifically, the responses of mortality by sex and life stage as well as those of marital fertility to price variations and landholding were largely unchanged even after we divided the entire period into the two sub-periods. The effects of rice price and landholding on out-migration also did not change much, except that the size of the negative effect of rice price variations on male out-migration more than doubled in the nineteenth century, compared to that in the eighteenth century.

By contrast, the nature of nuptiality responses to price fluctuations and landholding differed substantially between the sub-periods of 1716—99 and 1800-70.²⁹ Examining the responses of all first marriages by sex for the two sub-periods, we found that it was only in the nineteenth century (1800—70) that the probability of first marriage for both sexes declined significantly when local economic conditions deteriorated, whereas the probability of first marriages was not influenced by variations in local economic conditions in the eighteenth century (table not shown).³⁰ On the other hand, the probability of male first marriage was significantly higher for those who belonged to wealthier households in the eighteenth century, but the effects of landholding became insignificant for male marriage in the nineteenth century.

Comparing these results with those on the pooled analysis shown in Table 17.5, we can conclude that the significant responses of male and female first marriages to local rice price fluctuations were due largely to the significant nuptiality responses of both sexes concentrated in the nineteenth century (1800—70). The significant effect of household landholding on the probability of male first marriage found by the pooled analysis was due primarily to significant differentials in the probability of male first marriage by household landholding concentrated in the eighteenth century (1716-99).

7.