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Multilingual Demographic Dictionary, second unified edition, English volume

Survivorship function

Multilingual Demographic Dictionary, second unified edition, English vol.
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Survivorship function  (SURVIVORSHIP function)

The course of mortality throughout the life cycle may be described by a life table 1. A life table consists of several life table functions 2, all of which are mathematically related and may be generally derived when the value of one of them is known. The survivorship function 3 shows the number of survivors 4 of a cohort (116-2) of births to various exact ages (322-7) on the assumption that the cohort is subjected to the rates of mortality shown. The number of births in the original cohort is known as the radix 5 of the life table and the process by which the original cohort is reduced is known as attrition 6.

  • 4. The number of survivors to exact age x is denoted by lx .
  • 5. The radix is usually a power of 10: 10,000 or 100,000 for example.