Long-term sickness and invalidity benefits: Forecasting and other actuarial problems

Abstract

It is proposed to discuss the actuarial problems associated with the management of long-term sickness and invalidity benefits. The emphasis is on benefits provided by social security schemes (with particular reference to National Insurance benefit in the UK), but the main points are relevant to private sector benefits including permanent health insurance (PHI).The plan of the paper is as follows. We describe in Section 2 the nature of long-term invalidity benefit provided by the British social security system and then consider in Section 3 the problems associated with defining disability. A discussion of the differences between the incidence of morbidity and the making of an insurance claim leads to consideration of selection and moral hazard (Section 4). We then examine in Section 5 the methodology for analysing costs and estimating future costs with particular reference to the development within the Government Actuary's Department (GAD) of a model based on an incidence and survivorship approach to invalidity benefit and the debate aroused by CMI Report No. 7 on the same topic5. The paper then presents an analysis of recent trends in disability claim rates (Section 6) and incidence and termination rates (Sections 7 and 8) based on invalidity benefit within the British social security system, as well as PHI and the experience of other countries. Attempts are then made in Section 9 to explain these trends and the upward trend in financial costs for disability benefits experienced by many social security systems. The paper concludes with an examination of two areas of current interest, viz. sex differences in morbidity rates and claim rates (Section 10) and the relationship between claim rates and the prevailing level of unemployment (Section 11).