Lorenz non-consistent welfare and inequality measurement

Typical welfare and inequality measures are required to be Lorenz consistent which guarantees that inequality decreases and welfare increases as a result of a progressive transfer. We explore the implications for welfare and inequality measurement of substituting the weaker absolute differentials and deprivation quasi-orderings for the Lorenz quasi-ordering. Restricting attention to distributions of equal means, we show that the utilitarian model - the so-called expected utility model in the theory of risk - does not permit one to make a distinction between the views embedded in the differentials, deprivation and Lorenz quasi-orderings. In contrast it is possible within the dual model of M. Yaari (Econometrica 55 (1987), 99–115) to derive the restrictions to be placed on the weighting function which guarantee that the corresponding welfare orderings are consistent with the differentials and deprivation quasi-orderings respectively. Finally we drop the equal mean condition and indicate the implications of our approach for the absolute ethical inequality indices.     

Optimal Ordering Policies for Stochastic Inventory Problems with Observed Information Delays

Information delays exist in an inventory system when it takes time to collect, process, validate, and transmit inventory/demand data. A general framework is developed in this paper to describe information flows in an inventory system with information delays. We characterize the sufficient statistics for making optimal decisions. When the ordering cost is linear, the optimality of a state‐dependent base‐stock policy is established even when information flows are allowed to cross over time. Additional insights into the problem are obtained via a comparison between our models and the models with stochastic order lead times. We also show that inventory can substitute for information and vice versa.     

On proximity between PCA in the frequency domain and usual PCA

The principal components analysis (PCA) in the frequency domain of a stationary p-dimensional time series (X _n ) _n∈? leads to a summarizing time series written as a linear combination series X′ _n =∑ _m C _m ° X _n?m . Therefore, we observe that, when the coefficients C _m , m≠0, are close to 0, this PCA is close to the usual PCA, that is the PCA in the temporal domain. When the coefficients tend to 0, the corresponding limit is said to satisfy a property noted 𝒫, of which we will study the consequences. Finally, we will examine, for any series, the proximity between the two PCAs.     

Les tâches de l'OIT à l'heure de son centenaire

Les principes – énoncés dans sa Constitution et dans la Déclaration de Philadelphie – qui définissent les missions de l'OIT n'ont rien perdu de leur valeur ni de leur actualité. En revanche, les conditions dans lesquelles ces missions s'exercent ont profondément changé. Le monde du travail est aujourd'hui le théâtre de bouleversements écologiques, technologiques et institutionnels, qui sont autant de défis à relever. La contribution de l'OIT à cette tâche devrait s'ordonner autour de trois principes, dont la mise en œuvre correspond à ses missions constitutionnelles: les principes de solidarité, de démocratie économique et de responsabilité socio-écologique.     

Walk-in clinic counselling for emotional regulation with low-needs youth on the autism spectrum

A single-session consultation model for low-needs youth on the autism spectrum is presented with the mental health concern of emotional self-regulation, a common issue in family psychotherapy. This research is contextualised within the growing field of short-term therapy as it intersects the growing demand to therapeutically address clients on the autism spectrum. The treatment intervention is delineated through five sequential phases within the walk-in clinic setting for the practitioner clinician. A rationale, overview, and instruction for the practitioner clinician utilising this novel model is provided through a case study format. By using a more structured and integrated approach to treatment, organised through an externalised metaphor, it is suggested that the current model will be more effective for this specific clinical population. Additionally, a case illustration is provided that scaffolds the treatment model, which includes table formats and pictures. The case study illustrates the self-regulation map metaphor visually and interactively linking client challenges, strategies, and motivations simultaneously on multiple electronic devices in session. Relevant works were selected to explore the effectiveness of single-session consultation models for those presenting on the autism spectrum. Treatment interventions for specific clinical populations are recommended, especially within walk-in clinic therapy. This clinical research introduces a paradigm shift towards therapeutically addressing emotional self-regulation with low-needs youth on the spectrum through virtual, interactive technology.     

Tribute to Jean-Yves Jaffray

Tribute to Jean-Yves Jaffray by the French Group of Decision Theory.     

Lower bounds and a tabu search algorithm for the minimum deficiency problem

An edge coloring of a graph G=(V,E) is a function c:E→ℕ that assigns a color c(e) to each edge e∈E such that c(e)≠c(e′) whenever e and e′ have a common endpoint. Denoting S _v (G,c) the set of colors assigned to the edges incident to a vertex v∈V, and D _v (G,c) the minimum number of integers which must be added to S _v (G,c) to form an interval, the deficiency D(G,c) of an edge coloring c is defined as the sum ∑ _v∈V D _v (G,c), and the span of c is the number of colors used in c. The problem of finding, for a given graph, an edge coloring with a minimum deficiency is NP-hard. We give new lower bounds on the minimum deficiency of an edge coloring and on the span of edge colorings with minimum deficiency. We also propose a tabu search algorithm to solve the minimum deficiency problem and report experiments on various graph instances, some of them having a known optimal deficiency.     

Gender homophily from spatial behavior in a primary school: A sociometric study

We investigate gender homophily in the spatial proximity of children (6–12 years old) in a French primary school, using time-resolved data on face-to-face proximity recorded by means of wearable sensors. For strong ties, i.e., for pairs of children who interact more than a defined threshold, we find statistical evidence of gender preference that increases with grade. For weak ties, conversely, gender homophily is negatively correlated with grade for girls, and positively correlated with grade for boys. This different evolution with grade of weak and strong ties exposes a contrasted picture of gender homophily.     

Inequality decomposition values: the trade-off between marginality and efficiency

This paper presents a general procedure for decomposing income inequality measures by income sources. The methods of decomposition proposed are based on the Shapley value and extensions of the Shapley value of transferable utility cooperative games. In particular, we find that Owen’s value can find an interesting application in this context.We show that the axiomatization by the potential of Hart and Mas-Colell remains valid in the presence of the domain restriction of inequality indices. We also examine the properties of these decomposition rules and perform a comparison with Shorrocks’ decomposition rule properties.