THE ESTIMATION OF HEALTH EXPECTANCIES FROM CROSS-LONGITUDINAL SURVEYS

The method of maximum likelihood is used to estimate parameterized transition probabilities of a non-homogeneous Markov chain model of movements between the health states disability-free, disabled, and death. A complication is that individuals are observed at irregular intervals, implying that particular attention must be paid to computational issues. Numerical results including estimated health expectancies and their standard errors are given for data from the Longitudinal Study on Aging (LSOA) of 1984-86-88-90 (Kovar et al. 1992). The weak ergodicity of prevalence on the non-absorbing states is established and supports the hypothesis of the compression of morbidity.