Timing contradictions in von Neumann and Morgenstern's axioms and in savage's ‘sure-thing’ proof

At the point of choice, let N be the delay in learning the outcome. Then von Neumann and Morgenstern's postulates contradictorily imply that N = 0 and N > 0. As a consequence, Savage's sure-thing proof, which has bestowed on expected utility theory most of its normative appeal, depends on inconsistent assumptions. Further, the validity of Savage's proof cannot be retrieved by minimizing N > 0, by making the delay a mere moment or so. The historical origins of these contradictions are traced to (i) von Neumann and Morgenstern inadvertently limiting their risk model to the certain period, that is the period after gamblers learn the outcome(s), and (ii) Savage's use of the sure-thing principle for analysing atemporally but also quite formally compound gambles [Savage, 1954, p. 23].     

Physical, social and emotional function after work accidents: a medicolegal perspective

The aim of this study was to analyse social and functional consequences of work accidents in a group of workers' compensation claimants who had been referred from the National Insurance Administration for a medicolegal assessment. The injured workers were evaluated on average 3 years after their accidents. Their medical records were analysed, and each injury was scored according to the Abbreviated Injury Scale (AIS). Participants completed the Short Form Questionnaire (SF-36). Factors relating to outcome on SF-36 were analysed using univariate and multivariate methods. 191 claimants returned the SF-36 (62%), 83% of the respondents had an AIS score of less than two, 33% reported working full time. Compared to population-based norms, the respondents reported significantly reduced health on all eight scales of SF-36. Better health and function was mainly associated with a higher level of education and more serious injuries. The extent of social support in the workplace after the accident was only partly related to outcome. The importance of psychosocial factors when making injury assessments in a medicolegal setting is highlighted.     

Measuring and evaluating school performance: an investigation of status and growth-based achievement indicators

Several school performance indices were evaluated using achievement data from multiple longitudinally matched middle school student cohorts in a large district in the southwestern United States. Measures designed to index the within-cohort achievement status and growth of students as well as the status and growth-based changes that occur over years between different student cohorts were studied. Within- and between-cohort status and growth-based estimates of school performance were generated by applying simple and relatively complex statistical models to the longitudinal time-series data obtained on students. Results indicated that within-cohort status-based estimates were closely related to student demographics and between-cohort estimates were associated with cohort enrollment size and initial performance level. These results suggest that schools may often be rewarded and penalized on the basis of factors over which school personnel have limited or no control. Implications for the measurement and evaluation of school performance are discussed.     

SOGS and CGPI: Parallel Comparison on a Diverse Population

The Northern Territory of Australia, one of the most demographically and socially diverse jurisdictions in the country, conducted its first population-based gambling and problem gambling prevalence survey in 2005. Both the South Oaks Gambling Screen (SOGS) and the Canadian Problem Gambling Index (CPGI) were administered to the same sample of respondents. Using data from this survey, the current paper presents a parallel comparison of the respective screens with particular reference to gender, region, and the socio-demographic characteristics of respondents. The respective screens produced significantly different groups of problem gamblers as measured by their association with a range of socio-demographic variables. Specifically, the large number of SOGS items related to money issues may cause selective overrepresentation among low socioeconomic groups, including Indigenous people, who exist in relatively high proportions in the Northern Territory. In addition, there existed substantial gender-based differences within screens. Identified female problem gamblers were associated with household level variables (i.e. employment status, household type and marital status), while males were associated with socio-economic variables including language, education, and income. Further research is required to validate the use of problem gambling screens within the Indigenous population and to understand the role of gender in the experience and categorisation of problem gambling.     

The strength of sensitivity to ambiguity

We report an experiment where each subject’s ambiguity sensitivity is measured by an ambiguity premium, a concept analogous to and comparable with a risk premium. In our design, some tasks feature known objective risks and others uncertainty about which subjects have imperfect, heterogeneous, information (“ambiguous tasks”). We show how the smooth ambiguity model can be used to calculate ambiguity premia. A distinctive feature of our approach is estimation of each subject’s subjective beliefs about the uncertainty in ambiguous tasks. We find considerable heterogeneity among subjects in beliefs and ambiguity premia; and that, on average, ambiguity sensitivity is about as strong as risk sensitivity.     

Issues in Complementary Health Insurance in Belgium

This article attempts to assess the increasing role of complementary social insurance in healthcare in Belgium. As different players attempt to fill in the lacunae of the statutory social security scheme, the demarcation of their sphere of action and of their mutual relationship is becoming problematic. It is therefore interesting to see the evolution of solidarity and selectivity. The analysis of both categories and products in complementary health insurance indicates the limitations and the bottlenecks in coming years for the social security scheme on the one hand and complementary social insurance on the other.     

Homebirth, freebirth and doulas: casualty and consequences of a broken maternity system

In Australia private homebirth remains unfunded and uninsured and publicly funded homebirth models are not widely available. Doulas are increasingly hired by women for support during childbirth and freebirth (birth intentionally unattended by a health professional) appears to be on the rise. The recently released Improving Maternity Services in Australia--The Report of the Maternity Services Review (MSR) exclude homebirth from the funding and insurance reforms proposed. Drawing on recent research we argue that homebirth has become a casualty of a broken maternity system. The recent rise in the numbers of women employing doulas and choosing to birth at home unattended by any health professional, we argue, is in part a consequence of not adequately meeting the needs of women for continuity of midwifery care and non-medicalised birthing options.