Browsing by Author "Dorrington, R E"
Now showing 1 - 5 of 5
Results Per Page
Sort Options
- ItemOpen AccessAn investigation of the mortality of South African assured lives(2005) O'Malley, B R; Dorrington, R E; Jurisich, S C; Valentini, J A; Cohen, T M; Ross, B JThis paper outlines the findings of an investigation of the mortality of South African assured lives, covering the period 1995 to 1998. The investigation was carried out by the Continuous Statistical Investigations (CSI) Committee of the Actuarial Society of South Africa (ASSA). Some of the major findings of the investigation were worsening mortality below age 50, general improvements in mortality above age 50, substantial differences in mortality between the different socio-economic classes and signs of anti-selection below age 50, especially in the better socioeconomic classes.
- ItemOpen AccessModelling the mortality of members of group schemes in South Africa(Acturial Society of South Africa, 2013) Clur, J C; Dorrington, R E; Schriek, K A; Lewis, P LIn this paper, the methodology underlying the graduation of the mortality of members of group schemes in South Africa underwritten by life insurance companies under group life-insurance arrangements is described and the results are presented. A multivariate parametric curve was fitted to the data for the working ages 25 to 65 and comparisons are made with the mortality rates from the SA85–90 ultimate rates for insured lives and the ASSA2008 AIDS and demographic model. The results show that the mortality of members of group schemes is lower than that of the general population, mortality decreasing with increasing salary, as would be expected. For males it was found that there were differences in mortality rates by industry for a given salary band, whereas for females these differences only occurred in the lower salary bands. Furthermore, there is evidence of the healthy-worker effect at ages 60 and above, where the mortality rates appear to level off or even decrease as age increases. This contrasts with the mortality rates from the SA85–90 ultimate rates for insured lives and the ASSA2008 AIDS and demographic model, which increase exponentially.
- ItemOpen AccessThe mortality of members of group schemes in South Africa(Acturial Society of South Africa, 2013) Schriek, K A; Lewis, P L; Clur, J C; Dorrington, R EIn this paper, the mortality of members of group schemes underwritten by South African life insurance companies is investigated. The research provides some indication of the level or mortality of this population as a whole, which apart from being useful for costing group schemes in future could be used, to the extent that these data represent the mortality of those in formal employment, in the costing of a national retirement scheme. Rates of mortality are investigated by several demographic factors such as age, sex, salary and industry of employment.
- ItemOpen AccessSouth African Annuitant Standard Mortality Tables 1996-2000 (SAIML98 and SAIFL98)(Actuarial Society of South Africa, 2007) Dorrington, R E; Tootla, SThis paper describes the data and the processes used to produce the first standard tables of mortality of South African immediate annuitants. A parametric curve was fitted to the data from the normal retirement ages up to age 85. Below the normal retirement ages the rates increasingly reflected the impact of higher mortality due to ill health retirements and so the curve was blended into that of the most recent standard table of life assured mortality (SA85 90). Above age 85 the estimates were thought to be unreliable and the extrapolation of the curve fit to the younger ages did not allow for the expected fall in the rate of increase in the rates with age. Thus rates above this age were estimated using a relationship proposed by Coale and Kisker. It was not possible to produce select rates or to decide on a trend in these rates over time.
- ItemOpen AccessThe potential effect of an HIV/AIDS vaccine in South Africa(2007) Dorrington, R E; Johnson, L FThis paper presents a model for assessing the potential effect of an HIV/AIDS vaccine in South Africa, and for calculating the amount of vaccine that would be required. A number of different hypothetical vaccine profiles and vaccine distribution strategies are considered. Results suggest that a sterilising vaccine could reduce the HIV incidence between 2015 and 2025 by up to 50%, while a disease modifying vaccine would be unlikely to reduce HIV incidence by more than a third. The effect on AIDS mortality over the same period would be substantially smaller, and it is unlikely that any preventive vaccine would reduce AIDS mortality by more than 10% between 2015 and 2025.