Description: Demography is a very exciting subject. With a simple mathematical model, students can project a country's population forward 25, 59, 75 even 100 years. This paper will focus on six ideas from demography. They all can be useful to an actuary, yet none of them would be considered at any length if the actuary didn’t study demography.

Description: This paper describes risk-factor-dependent multiple decrements and actuarial cost functions as a general compartment model, a discrete time and discrete state stochastic model of morbidity and mortality processes. For large numbers of risk factors, the model is extended to its natural continuous time and state form. From Transactions of Society of Actuaries 1991, Vol. 43.