Defined terms for the annuity market and lifetime income landscape.
Force of mortality is the continuous-time formulation of the hazard rate for death at a specified age — the instantaneous rate at which death is occurring among those still alive at that age, expressed as a rate per unit of time.
The gender mortality differential is the consistent empirical finding that women live longer than men in essentially all human populations, with the difference in the United States measured at approximately 5 years of life expectancy at birth as of 2024.
Gompertz law is the empirical regularity, first identified by Benjamin Gompertz in 1825, that adult mortality rates rise approximately exponentially with age across much of the adult lifespan, providing a compact functional form for representing age-specific mortality.
Hazard rate is the instantaneous rate at which an event of interest occurs at a specified age, conditional on the event not yet having occurred — in mortality applications, the rate of death at a given age among those still alive at that age.
Healthspan versus lifespan is the distinction between the years of life lived in good health (healthspan) and total years of life (lifespan), with the gap between them representing the years lived with significant disease, disability, or functional limitation.
