A Risk-Benefit Analysis of French High Fish Consumption: A QALY Approach

The health risk and the nutritional benefit of a food are usually assessed separately. Toxicologists recommend limiting the consumption of certain fish because of methylmercury; while nutritionists recommend eating more oily fish because of omega 3. A common evaluation is imperative to provide coherent recommendations. In order to evaluate the risks along with the benefits related to fish consumption, a common metric based on the quality-adjusted life year (QALY) method has been used. The impact of a theoretical change from a medium n-3 PUFAs intake to a high intake is studied, in terms of the cardiovascular system (CHD mortality, stroke mortality and morbidity) and on fetal neuronal development (IQ loss or gain). This application can be considered as a sensitive analysis of the model used and looks at the impact of changing the dose-response relationships between cardiovascular diseases and n-3 PUFAs intakes. Results show that increasing fish consumption may have a beneficial impact on health. However, the confidence interval of the overall estimation has a negative lower bound, which means that this increase in fish consumption may have a negative impact due to MeHg contamination. Some limits of the QALY approach are identified. The first concerns determination of the dose-response relationships. The second concerns the economic origins of the approach and of individual preferences. Finally, since only one beneficial aspect and one risk element were studied, consideration should be given to how other beneficial and risk components may be integrated in the model.     

The Intervening Role of Relational Aggression between Psychological Control and Friendship Quality

This study investigated the associations among psychologically controlling parenting, relational aggression, friendship quality, and loneliness during adolescence. A model was proposed in which relational aggression plays an intervening role in the relations between both parental psychological control and friendship outcomes. In a sample comprised of middle adolescents and their parents, process analyses revealed that psychological control (indexed by parent and adolescent reports) positively predicted adolescents' self-reported relational aggression that, in turn, negatively predicted friendship quality and positively predicted loneliness. The model held for both mothers and fathers and was not moderated by adolescent gender. The discussion focuses on possible mechanisms explaining the relations among psychological control, relational aggression, and friendship outcomes.     

Continuity and equity with infinite horizons

 In an infinite dimensional space, e.g. the set of infinite utility streams, there is no natural topology and the content of continuity is manipulable. Different desirable properties induce different topologies. We consider three properties: effectiveness. l ₁-summability and equity. In view of effectivity, the product topology is the most favourable one. The strict topology is the largest topology for which all the continuous linear maps are l ₁-summable. However, both topologies are myopic and conflict with the principle of equity. In case equity is desirable, the sup topology comes forward. Received: 15 April 1993 / Accepted: 22 April 1996     

Welfarist evaluations of decision rules for boards of representatives

We consider a decision board with representatives who vote on proposals on behalf of their constituencies. We look for decision rules that realize utilitarian and (welfarist) egalitarian ideals. We set up a simple model and obtain roughly the following results. If the interests of people from the same constituency are uncorrelated, then a weighted rule with square root weights does best in terms of both ideals. If there are perfect correlations, then the utilitarian ideal requires proportional weights, whereas the egalitarian ideal requires equal weights. We investigate correlations that are in between these extremes and provide analytic arguments to connect our results to Barberà and Jackson (J Polit Econ 114(2):317–339, 2006) and to Banzhaf voting power.     

Consistent deconvolution in density estimation

Suppose we have n observations from X = Y + Z, where Z is a noise component with known distribution, and Y has an unknown density f. When the characteristic function of Z is nonzero almost everywhere, we show that it is possible to construct a density estimate f_n such that for all f, Iim_n| |=0.     

A note on Chichilnisky's social choice paradox

One of the main results in topological social choice states the non-existence of a continuous, anonymous, and unanimous aggregation rule on spheres. This note provides a proof based upon simple methods such as integration.     

The Food Crisis and its Impacts on Poverty in Senegal and Mali: Crossed Destinies

This article uses two CGE macro‐micro models to analyse the distributional impact of the food crisis and policy responses in two neighbouring African countries, both of which are strongly dependent on agriculture. The approach captures structural differences at both the macro and micro level for household income and expenditure structures, and the results reveal differences for poverty impact at the national and sub‐group levels, as well as for inequality and pro‐poor analysis. The importance of country‐specific analysis and the risk of extrapolating conclusions from one country to another are also highlighted.     

A latent process model for dementia and psychometric tests

We jointly model longitudinal values of a psychometric test and diagnosis of dementia. The model is based on a continuous-time latent process representing cognitive ability. The link between the latent process and the observations is modeled in two phases. Intermediate variables are noisy observations of the latent process; scores of the psychometric test and diagnosis of dementia are obtained by categorizing these intermediate variables. We propose maximum likelihood inference for this model and we propose algorithms for performing this task. We estimated the parameters of such a model using the data of the 5 year follow-up of the PAQUID study. In particular this analysis yielded interesting results about the effect of educational level on both latent cognitive ability and specific performance in the mini mental test examination. The predictive ability of the model is illustrated by predicting diagnosis of dementia at the 8 year follow-up of the PAQUID study based on the information from the first 5 years.