摘要：The standard period life table is based entirely on the death probabilities of the given period. Popular (not expert) usage of life expectancies from a period table typically ignores the fact that the expectancies make no allowance for future declines in mortality rates. But the historical record provides overwhelming evidence to suggest that declines will continue, and the period expectancies can therefore be misleading, in a practical context. We propose a “dynamic” extension of the period table that draws out the implications, for survivorship and life expectancy, of observed rates of change of death probabilities.
关键词：dynamic extension;life expectancy;period life expectancy
