Multiple-output quantile regression through optimal quantization

A new nonparametric quantile regression method based on the concept of optimal quantization was developed recently and was showed to provide estimators that often dominate their classical, kernel-type, competitors. In the present work, we extend this method to multiple-output regression problems. We show how quantization allows approximating population multiple-output regression quantiles based on halfspace depth. We prove that this approximation becomes arbitrarily accurate as the size of the quantization grid goes to infinity. We also derive a weak consistency result for a sample version of the proposed regression quantiles. Through simulations, we compare the performances of our estimators with (local constant and local bilinear) kernel competitors. The results reveal that the proposed quantization-based estimators, which are local constant in nature, outperform their kernel counterparts and even often dominate their local bilinear kernel competitors. The various approaches are also compared on artificial and real data.     

Academic Paths,Ageing and the Living Conditions of Students in the Late 20th Century*

Le monde étudiant est profondément marqué par la diversité des tra‐jectoires individuelles, qui sont souvent très éloignées d'un déroule‐ment linéaire des études. Les conséquences sur l'âge des étudiants sont majeures, et la condition étudiante ne peut plus être définie comme une expérience strictement juvénile. Or, entre 20 et 30 ans, l'âge engendre des impératifs différentiels sur le plan des conditions et des modes de vie qui ne sont pas toujours compatibles avec la condition étudiante classique. Cette étude des parcours et de la situation financière des étudiants des universités québécoises de langue françhise et anglaise montre comment s'opère la déconnexion entre jeunesse et condition étudiante, et comment cette déconnexion influe sur la différenciation des conditions de vie et de financement des études. Student life is profoundly marked by the diversity of individual trajectories, which are in stark contrast with the linear path traditionally taken by students. The impact on the age of the student population is significant: indeed, student life can no longer be qualified as strictly for the young. Between the ages of 20 and 30 years, different imperatives come into play in terms of living conditions and lifestyle. These imperatives are not always compatible with the conditions of classic student life. This study of the academic paths and the financial situation of Quebec university students shows how the disconnection between student condition and youth occurs and how this disconnection impacts the differentiation of student's living conditions and modes of financing university studies.     

The use of pesticides in French viticulture: a badly controlled technology transfer!

The use of pesticides is one of the techniques employed in modern agriculture and in particular in intensive agriculture. The risks for the environment and for worker health have been debated in western countries for about ten years. Recent developments in epidemiology, toxicology and ergotoxicology have clearly revealed that pesticides could harm the health of farmers (cancers, neurological diseases and reproductive disorders). Failures and shortcomings in the risk prevention systems have also come to light. This paper aims to address the risks associated to the use of pesticides in French vineyards. The chosen approach draws from an anthropological approach as well as from developments in ergotoxicology applied to the French vineyard work. We shall discuss the use of pesticides from the point of view of the transfer of technology. Our recent research has shown that this technology transfer was not completely controlled by the different stakeholders.     

“From cause to cure”: A qualitative study on contemporary forms of mother blaming experienced by mothers of young children with autism spectrum disorder

ABSTRACT

In the past, the behaviours and personalities of mothers have been identified as potential causes of autism. More recently, other etiological hypotheses have been used to explain autism spectrum disorder, suggesting that this specific type of mother-blaming is now uncommon. However, some authors have pointed out that mothers are still being held responsible for their children’s condition and behaviours, as they are now expected to extensively promote their children’s development. The present article explores contemporary forms of mother-blaming experienced by thirteen mothers of children with autism spectrum disorder. The results are discussed in relation to the consequences of mother-blaming, such as social isolation and health related problems. It is hoped that this article will encourage social workers and professionals to understand the mothers’ perspectives and to recognize the importance of supporting them without generating or increasing mother-blaming.     

Psychosocial Profile of Children Having Participated in an Intervention Program for Their Sexual Behavior Problems: The Predictor Role of Maltreatment

This study sought to verify if a history of maltreatment may predict the psychosocial profile of children who participated in an intervention program aiming at reducing sexual behavior problems. Data were collected at both the beginning and the end of the intervention program using a clinical protocol and standardized tests selected on the basis of the intervention targets. In general, the results indicate that children who had experienced maltreatment display a psychosocial profile that is similar to that of children who had not experienced maltreatment. However, children who had experienced psychological abuse or neglect may display greater externalized or sexualized behaviors, whereas children who have a parent who had been a victim of sexual abuse may display fewer sexualized behaviors.     

Optimal allocation mechanisms with type-dependent negative externalities

I analyze optimal auction design in the presence of linear type-dependent negative externalities. I characterize the properties of the optimal mechanism when externalities are “strongly decreasing” and “increasing” in the agent’s valuation and I discuss its implementation with sealed-bid auctions. Interestingly, bidding strategies are not necessarily increasing in valuations, and the optimal mechanism can be implemented by setting a price ceiling instead of a reserve price.     

Exploring Women's Retirement: Continuity,Context and Career Transition

This paper reports on an exploratory study examining women's views about and experiences of retirement. It has long been recognized that women's careers often follow a different path than men's due to the differential impact of family and domestic responsibilities and their relative underrepresentation at higher levels of organizations. However, many studies of retirement have implicitly assumed a conventional male career as the norm, where retirement is seen as marking a neat ending to continuous employment. This paper aims to present a richer understanding of women's retirement, utilizing contextual national data and qualitative analysis. The paper begins with a brief summary of literature looking at women's career development. We then explore the concept of retirement and consider current literature with regard to women's retirement. Following a brief discussion of our research approach, we provide some national context using quantitative data. We then discuss the qualitative findings, examining the areas of continuity and change that women experienced in retirement and exploring the factors that they felt enabled and constrained them.     

Rush and Procrastination Under Hyperbolic Discounting and Interdependent Activities

We analyze the decision of individuals with time-inconsistent preferences to invest in projects yielding either current costs and future benefits or current benefits and future costs. We show that competition between agents for the same project mitigates the tendency to procrastinate on the first type of activities (i.e. to undertake them too late) and to rush on the second one (i.e. to undertake them too early). Competition can therefore increase the expected welfare of each individual. On the contrary, complementarity of projects exacerbates the tendency to rush and to procrastinate and therefore it can decrease the expected welfare of each individual.