A cash flow model is proposed as a way of analysing uncertainty in the future development of a general insurance company. The company is modelled alongside the market in aggregate so that the impact of changes in premium rates relative to the market can be assessed. An extensive computer model is developed along these lines, intended for use in practical applications by actuaries advising the management of genera1 insurance companies. Simulation methods are used to explore the consequences of uncertainty, particularly in regard to inflation and investments. Some comments are made on the role of actuaries in general insurance. Alternative approaches to describing the behaviour of an insurance firm in the market are considered.

The authors discuss the investment of pension and other institutional funds. stressing a theme of investing to meet liabilities. Their aim is to stimulate debate by actuaries and the investment community, leading to the development of better approaches to pension fund investment and its monitoring.

The first part of the paper considers the matching of assets to liabilities, concentrating on a major principle applicable to actuarial valuations where assets and liabilities are mismatched.

The paper goes on to consider principles of institutional investment and includes discussions of the meaning and measurement of risk, the setting of investment objectives, decision-making, asset allocation and investment performance monitoring.

The paper reviews the underwriting of life assurance and sickness benefits today. It considers both medical and non-medical aspects and how the extra risks should be costed. The paper also deals with financial underwriting. reassurance and the management of death claims. Although the paper presents a ‘state of the art’ picture, it also considers advances via on-line acceptance, expert systems and computer-based training.

The paper traces the history of the development of a with-profit system for a specialist unit-linked office. The marketing problem, to which this was the chosen solution, is discussed and a number of possible future developments are then considered. The second half of the paper is devoted to discussion of the question of matching assets and liabilities for the range of products developed. Although the paper deals with developments in a particular office the authors' intention is to provide a different perspective on the problems associated with conventional with-profit business which will be of more general interest.

The paper considers a number of methods of estimating the work time lost due to sickness, unemployment and stoppages. The most satisfactory approach suggested is based on a multiple state working life table. Numerical examples of the measurement of work time lost are provided for particular application to the actuarial assessment of damages (arising out of personal injury or fatal accident). Other applications, including the pricing of unemployment insurance, are also discussed.

The current state of knowledge on the epidemiology of HIV infection and AIDS is reviewed, with extensive references to the medical literature. The particular focus is on those aspects of the epidemiology of HIV infection which are of interest in the formulation of models for projecting the future spread of the virus and its impact in terms of numbers of cases of AIDS and deaths from AIDS.

The paper reviews the mathematical models of transmission of infection that have been put forward for representing the spread of HIV infection and AIDS. It describes and compares the main models that have been proposed and thereby provides some guidance on how such models might be constructed and utilised. There is also discussion of the importance of constructing such mathematical models of transmission of infection which further our understanding of the transmission dynamics of the epidemic and help to identify important epidemiological parameters and their likely influence on the epidemic's course.

The paper presents a theoretical framework for the valuation of a general insurance company to actuaries, but also aims to provide reference work for non-actuarial users of appraised values. It distinguishes between the price that may be paid for an insurance operation from what may be called the economic or appraised value. The paper describes the elements of the appraised value calculation, selection of parameters, the uses of such evaluations and explores the future development into explicit stochastic modelling rather than the implicit methodology. Theoretical and practical considerations are illustrated and example valuations of a single line insurer are given.

In AIDS Bulletins Nos. 1 to 4 the Institute of Actuaries AIDS Working Party presented projections of HIV infection and AIDS based on a model developed by Wilkie. This paper explores the sensitivity of those projections to the various different assumptions which have to be made and presents results on a number of alternative sets of assumptions.

This note considers the mortality table functions, and shows that the usual formulae hold under less restrictive assumptions than those usually made. The foundations of the theory of multiple-decrement tables are also considered, in the context of probability theory.

The ‘law of mortality’ proposed by Heligman and Pollard is compared with the law of Gompertz and with English Life Table No. 14. Some new mathematical results are derived, including specific equations for the curve of deaths. Some numerical illustrations are given.

The paper comments on the estimation and sensitivity of the retail price inflation component of the stochastic financial model proposed by Professor Wilkie. Statistical tests provide evidence of nonindependence and non-normality of residuals, suggesting non-linearity. However, it is noted that the model is most sensitive to the assumption of long-term mean inflation.

The paper addresses the problem of estimating future claim payments from the ‘run-off’ of past claim payments. A model of the claim payment process is postulated. Results from risk theory are applied to give a model for the incremental paid claims data by development period. A fitting method is developed which takes account of the error structure of the data implied by the underlying model of the claim payment process. The application of a similar method to incremental incurred data is considered. A numerical example is given.

This note continues a regular series on mortality rates in Great Britain, showing the mortality experienced in each age-group in 1988 and comparing this for broad age-groups, on a standardised basis, with mortality in earlier years.