Unobserved individual frailty is prevalent and consequential in the population pattern of health and mortality. This study investigates how unobserved frailty may complicate the cohort trend in health disparities and life expectancy. We use the micro-simulation method based on a mathematical model of individual mortality hazard and group frailty distribution to generate an aggregate pattern of age-dependent mortality rate for less-educated (high school or less) and better-educated (any college) groups. We alter the values of the frailty variance to generate hypothetical mortality patterns and life expectancy to test the effect of unobserved frailty. Our exercises reveal that life expectancy gap between the two education groups can either widen or narrow across cohorts as a result of the change in frailty variance. Empirical analysis suggests mortality selection contributes up to 24% of the widening educational gap in life expectancy from the 1950s to 1960s birth cohorts in the United States.
Presented in Session 167. Modeling Mortality