MPIDR Working Paper
The decomposition of the difference between two healthy life expectancies: which formula is right?
MPIDR Working Paper WP-2017-016, 6 pages.
Rostock, Max-Planck-Institut für demografische Forschung (September 2017)
Revised January 2019
About two months ago, a colleague asked me to look at a preliminary version of a working paper written by him together with two other researchers. The topic of the paper was how patterns of morbidity prevalence influence the length of healthy life. Among other analyses, the authors presented an age decomposition of a change in healthy life expectancy (HLE). The text of the working paper included references to two studies published in the early 2000s, which were the first to introduce formulas for decomposing the difference between two HLE values by age, and by health and mortality within each age. In this note, we intend to clarify this apparent discrepancy by demonstrating 1) the correctness of the method by Andreev, Shkolnikov, and Begun 2002; and 2) the flaws in the method related to mortality components by Nusselder and Looman 2004.