Consistent Correction of International Migration Data for Sri Lanka,1971–81 1

Abstract

A new methodology is used here, to estimate net international emigration by age and sex from Sri Lanka between 1971 and 1981. The procedure starts with a set of preliminary estimates of census populations in 1971 and 1981 and intercensal births, deaths, and migrants. These preliminary estimates are corrected in such a way as to be consistent with a set of intercensal demographic balancing equations. The methodology, which is formulated in terms of finite-dimensional vector spaces and which involves an optimizing criterion, includes a weighting procedure by which the brunt of the corrections can be made to fall on the least reliable quantities, in this case migrants. The procedure also yields corrected estimates of population, births, deaths, and derived life tables.