This article aims to investigate the effect of sudden changes in external conditions on human mortality levels and age-patterns. Although several studies have analysed shocking events such as famines or deportations, a systematic assessment of the effect of the shock on the rate of mortality increase by age is missing. In the case of a shock, three scenarios may occur: mortality may be raised proportionally at all ages, more at older ages, or more at younger ages. Two cases of natural mortality experiments were analysed: Australian civilian prisoners in a Japanese camp during the Second World War and the Ukrainian Famine of 1933. The death rates of the prisoners of war were higher during imprisonment but the slope of the curve appeared to resemble that of the normal mortality regime. During the Ukrainian Famine, by contrast, the mortality curves in the different famine years were raised but the increase was smaller at old ages, resulting in different slopes. When mortality increases less at older ages, the evidence that selection could be the underlying mechanism appears to be weak and inconclusive. However, as other mechanisms could lead to similar patterns, more cases of natural morality experiments need to be analysed and more evidence collected.
Population (english Edition), 2013, Vol 68, Issue 2, p. 265-291