Demographic Analysis and Evaluation Workshop on Demographic Analysis and Evaluation 1

Mortality: Construction of Composite Life Tables

Construction of a Complete Life Table Situations arise where one might want to derive complete life tables from (1) an incomplete set of life table values, often but not always involving estimates of under-5 mortality, or from (2) information on child survivorship and conditional or unconditional survivorship probabilities for adult ages. Because child and adult mortality patterns may not follow the same regional model life table pattern, the second situation may require some smoothing in addition to linkage.

Smoothing and Interpolation or Extrapolation of an Incomplete Set of Mortality Indicators Manual X (chapter VI) describes methods for constructing complete, or composite, life tables from less-than-complete inputs. Smoothing and interpolation of an incomplete set of survivorship probablility estimates, l(x), using a standard life table pattern and the logit system. Manual X. Alternative tool: MORTPAK/BESTFT, which uses principal components, a least squares criteria for fitting, and a standard life table pattern to identify a composite life table that best fits a set of q(x) values

Smoothing and Interpolation or Extrapolation of an Incomplete Set of Mortality Indicators Linkage of child survivorship probabilities with conditional adult survivorship probabilities. Conditional adult survivorship probabilities such as l(35)/l(20) from widowhood or maternal or paternal orphanhood techniques may be combined with a child survivorship-based estimate again using a standard life table pattern and the logit system.

Smoothing and Interpolation or Extrapolation of an Incomplete Set of Mortality Indicators Use of Coale-Demeny (or United Nations) model life tables. A simpler approach would extend mortality level from childhood to young adulthood with reference to a standard model life table, generating a pivotal l(x) value, constructing the remainder of the composite life table without smoothing or by using the product of the pivotal l(x) and conditional adult survivorship probabilities. Tool: MORTPAK/MATCH to bridge the mortality indicator gap between child mortality and a pivotal adult conditional mortality

Smoothing and Interpolation or Extrapolation of an Incomplete Set of Mortality Indicators Grafting child mortality and adult mortality m(x) values from deaths reported in a census, after adjustment of those deaths. Brass’ Growth-balance technique and the Preston-Coale method estimate adjustment factors for either registered deaths or deaths reported for a fixed reference period prior to a census. Adjusted m(x) values – based on adjusted deaths and estimated denominator population -- from age 5 upward can be combined with child survivorship-based estimates of under-5 m(x)s to construct a composite set of life table m(x)s. Tools: LTPOPDTH, MATCH, LTMXQXAD.

Smoothing and Interpolation or Extrapolation of an Incomplete Set of Mortality Indicators Constructing a composite life table using indices of child and adult mortality. MORTPAK version 4.3 offers another tool for constructing a composite life table based on indices of child and adult (either m(x) or conditional) values.) MORTPAK’s COMBIN and BESTFT use principal components estimation for the estimation. Tools: COMBIN, BESTFT.

Further Reading United Nations. 1983. Manual X. Indirect Techniques for Demographic Estimation. ST/ESA/Ser.A/81. New York, chapter VI. _____. 2013. MORTPAK for Windows, version 4.3. New York.