The Deep Side of Preference Theory

An individual is said to have a taste for a particular menu, i.e. a subset of available commodities, if he is indifferent between all commodity bundles that contain the same quantity for each commodity which actually is in the menu, whatever the rest of the bundle. Then, a taste is directly defined as a deep property of preferences. As a first result, it is shown that a complete and transitive preference relation over the commodity bundles is equivalent to regular tastes where regularity means that tastes can be derived from a pure qualitative relation between the different commodities. Besides, a preference family based on preference relations corresponding to each particular commodity is said to be rationalizable if there exists a metapreference over commodity bundles which consistently summarizes the preference family and then allows to decide. As a second result, it is shown that if a preference family is rationalizable, then the tastes are organized thanks to a reflexive and transitive qualitative relation between the different commodities.     

Optimizing trial design in pharmacogenetics research: comparing a fixed parallel group,group sequential,and adaptive selection design on sample size requirements

Two‐stage clinical trial designs may be efficient in pharmacogenetics research when there is some but inconclusive evidence of effect modification by a genomic marker. Two‐stage designs allow to stop early for efficacy or futility and can offer the additional opportunity to enrich the study population to a specific patient subgroup after an interim analysis. This study compared sample size requirements for fixed parallel group, group sequential, and adaptive selection designs with equal overall power and control of the family‐wise type I error rate. The designs were evaluated across scenarios that defined the effect sizes in the marker positive and marker negative subgroups and the prevalence of marker positive patients in the overall study population. Effect sizes were chosen to reflect realistic planning scenarios, where at least some effect is present in the marker negative subgroup. In addition, scenarios were considered in which the assumed ‘true’ subgroup effects (i.e., the postulated effects) differed from those hypothesized at the planning stage. As expected, both two‐stage designs generally required fewer patients than a fixed parallel group design, and the advantage increased as the difference between subgroups increased. The adaptive selection design added little further reduction in sample size, as compared with the group sequential design, when the postulated effect sizes were equal to those hypothesized at the planning stage. However, when the postulated effects deviated strongly in favor of enrichment, the comparative advantage of the adaptive selection design increased, which precisely reflects the adaptive nature of the design. Copyright © 2013 John Wiley & Sons, Ltd.     

LIFE‐CYCLE PREFERENCES REVISITED

An axiomatic construction for life‐cycle preferences accounting for the finiteness and the randomness of life duration is provided. We emphasize the role of intertemporal correlation aversion and explain why multiplicative preferences provide an interesting alternative to additive preferences, allowing risk aversion and intertemporal elasticity of substitution to be separated. Implications regarding the shape of the optimal consumption profiles are discussed.     

Un critère de choix de variables en analyse en composantes principales fondé sur des modèles graphiques gaussiens particuliers

We focus on the problem of selection of a subset of the variables so as to preserve the multivariate data structure that a principal-components analysis of the initial variables would reveal. We propose a new method based on some adapted Gaussian graphical models. This method is then compared with those developed by Bonifas et al. (1984) and Krzanowski (1987a, b). It appears that the criteria for all methods consider the same correlation submatrices and often lead to similar results. The proposed approach offers some guidance as to the number of variables to be selected. In particular, Akaike's information criterion is used.     

Aggregation of preferences: The fuzzy case

The basic purpose of this paper is to link both theorems of impossibility and existence by introducing fuzzy relations of preference and an exogeneous requirement, the planner's one, and then proving the fundamental part played by the extremist agents, leximin and leximax. In other words, to bring out the link between the planner's requirement and the difficulty of the transition from individual to collective, as well as the theoric relation between this requirement and the extremist agents, we define a fuzzy behavior of preference which allows us to build up two determinant fuzzy coalitions. These coalitions will be the base of the planner's requirement and the link between pessimistic results (Arrow's impossibility) and optimistic ones (May's theorem of majority choice).     

Improving quality of life after breast cancer: prevention of other diseases

Many women with breast cancer will be diagnosed at an early stage through screening programmes. Furthermore, most women affected by breast cancer will not die from it but from other diseases, owing to recent improvements in treatment. This article assesses whether breast cancer survivors suffer more frequently from other diseases. Specifically, it examines whether they have a higher incidence of other cancers, cardiovascular events and osteoporotic fractures. Women with breast cancer and three or more co-morbid conditions have a 20-fold higher rate of mortality from causes other than breast cancer and a 4-fold higher rate of all-cause mortality when compared with patients who have none. Breast cancer survivors are at increased risk of other cancers, such as stomach, colorectal and lung. Radiotherapy, trastuzumab and aromatase inhibitors increase the risk of cardiovascular disease. However, tamoxifen does not, although it is associated with an increased risk of venous thromboembolism. Aromatase inhibitors, but not tamoxifen, increase the risk of osteoporotoic fracture and bisphosphonate therapy should be considered.     

Constructing undesirables: A critical discourse analysis of ‘othering’ within the Protecting Canada's Immigration System Act

Immigration policy in Canada has recently shifted, reflecting changes in other Western countries. We studied the discursive constructions of forced migrants within Bill C‐31 “Protecting Canada's Immigration System Act” and its associated Backgrounder documents published by the Canadian Government. The documents were analysed using an approach to critical discourse analysis adapted from Bacchi's (2009) methodology and informed by a theoretical framework of “othering”. Particular groups of migrants were represented as posing threats to the economy, the integrity of the refugee system, and national security. The documents offered three solutions: the creation of specific categories of migrants, an emphasis upon efficiency of the system, and expanded powers to the government. The problematization of asylum seekers as posing multiple threats to Canadian society obfuscates governmental responsibilities to this population and reflects common strategies of neoliberal governance.     

Who Wins and Who Loses? Public Transfer Accounts for US Generations Born 1850 to 2090

Public transfer programs in industrial countries are thought to benefit the elderly through pension and health care programs at the expense of the young and future generations. This intergenerational picture changes, however, if public education is also considered as a transfer program. We calculate the net present value at birth of benefits received minus taxes paid for US generations born 1850 to 2090. Surprisingly, all generations 1950 to 2050 are net gainers, while many current elderly are net losers. Windfall gains from starting Social Security and Medicare partially offset windfall losses from starting public education, roughly consistent with the arguments of Becker and Murphy.     

RISK AVERSION AND PLANNING HORIZONS

A number of empirical studies seem to reject the additive separability of preferences that is assumed in most theoretical models of the life cycle. We show that, when additive separability is abandoned and interactions between consumptions at different dates are taken into account, an interesting relation emerges between risk aversion and length of the planning horizon. Specifically, we show that when consumptions at different dates are specific substitutes, risk aversion increases with horizon length. This may explain the surprising empirical finding that individuals seem to increase the share of wealth held in risky assets as they become older. (JEL: D11, D91, G11)     

The Management of Redundancies in Europe: The Case of the Netherlands

The paper presents the findings of comparative and interdisciplinary legal and economic study on managing labour redundancies in seven EU member countries. It is structured for comparability between the systems examined. The introductory section contains an account of the evolution of the Dutch labour market, with special reference to redundancy trends, of the features of the programmes for managing redundancies, of the roles of firms and the ‘external environment’ in handling workforce adjustments. The second section presents a map of policies that work to prevent labour redundancies (preventive measures) such as flexibility, training etc. Next, the instruments for handling temporary labour redundancies (retentive measures) are examined (e.g. short-time working, temporary layoffs etc.). The following section is devoted to instruments and programmes involved in the management of permanent labour redundancies (expulsive measures), e.g. collective dismissals, severance pay etc. The final section provides an overall assessment of the Dutch system for managing labour redundancies, and briefly discusses the national debate on the prospects for reform, in light of the principles and policies of convergence set forth by the European Union.