Cohort Survival Consistency Checker
Project a census cohort forward with the life-table survival ratio L(x+n)/L(x) and report the percent closure error of the observed second census count against it.
Description
Project a census cohort forward with the life-table survival ratio L(x+n)/L(x) and report the percent closure error of the observed second census count against it.
Project a census cohort forward with the life-table survival ratio L(x+n)/L(x) and report the percent closure error of the observed second census count against it.1
When to use Cohort Survival Consistency Checker
Use this method when reconciling census counts, coverage, or intercensal components that share clearly stated reference dates and population definitions.
- Cohort at t1
- Cohort size enumerated at the first census.
- Observed at t2
- Observed size of the same birth cohort at the second census.
- Lx start
- Life table person-years Lx for the age group occupied at the first census.
- Lx after interval
- Life table person-years Lx for the age group occupied n years later.
- Tolerance
- Maximum absolute closure error in percent still judged consistent.
How the method works
- Survival ratio
- Cohort survival ratio implied by the life table.
- Expected
- Expected survivors obtained by multiplying the cohort by the ratio.
- Closure error
- Observed minus expected survivors as a percent of the expected value.
- Consistent
- True when the absolute closure error is within the tolerance.
Limitations and assumptions
Census-based estimates inherit omissions, duplications, age misstatement, boundary changes, and differences in reference dates. A small closure error does not prove that every component is complete or unbiased.
Alternative or Complementary measures
Compare the result with a post-enumeration survey, administrative registers, vital-statistics residual, or a second coverage method. Agreement between methods is more informative than a single closure estimate.
References
-
Census — Wikipedia contributors
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