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Using greediness for parameterization: the case of max and min (k, n − k)-cut
No full textMAX (k, n−k)-CUT (resp., MIN (k, n−k)-CUT) is a constrained version of MAX-CUT (resp.,MIN-CUT) where one has to find a bipartition of the vertex set into two subsets with respectively k and n − k vertices (n being the total number of vertices of the input graph) which maximizes (resp., minimizes) the number of edges going from one subset to the other. In this paper, we investigate the parameterized complexity of these two graph problems by considering several parameters, such as the value p of the solution, k, the size á of a minimum vertex cover and the treewidth tw of the input graph. We also give approximation schemata in FPT time for parameterizations which turn out to be W[1]-hard.nonnonouirechercheInternationa
Repérer les relations socio-affectives dans les groupes organisés. Le « détournement » de la grille d'observation de Bales
No full textEn sciences de gestion, peu de recherches ont étudié les relations socio-affectives. Ce constat s’explique notamment par le fait que les méthodes de recherche traditionnelles (questionnaire, entretien, enquête sociométrique) possèdent des limites lorsqu’il s’agit de repérer les affinités au sein des groupes organisés. Partant de ce constat, nous proposons ici une méthode originale d’identification des relations socio-affectives basée sur l’observation. Illustrée empiriquement, l’approche proposée consiste à observer à l’aide d’une grille de Bales les membres d’un groupe dans un contexte de communication informelle. Les spécificités de cette grille d’observation permettent, sur le modèle de la sociométrie, de repérer les attractions et les répulsions entre les membres d’un groupe. D’ordinaire utilisée pour comprendre les rôles incarnés par lesmembres d’un groupe attelés à une tâche commune, la grille de Balespourrait être détournée de son utilisation primaire pour devenir un outil d’identification des relations socio-affectives au sein d’un groupe organisé.nonouirechercheInternationa
MLiq a meta liquidity measure
No full textThe last crisis sheds light on the importance to consider liquidity risk in the financial industry. Indeed, liquidity had a predominant role in propagating the turmoil. In contrast, controlling for liquidity is a difficult task. The definition of liquidity links different dimensions that are impossible to fully capture together. As a consequence, there exist a lot of liquidity measures and we find in the literature some solutions to take into account more than one dimension of liquidity but also liquidity measures considering a long lasting liquidity problem. In this paper, we focus on drastic illiquidity events, i.e liquidity problems reported by several liquidity measures simultaneously. We propose a Meta-Measure of liquidity called MLiq and defined as the probability to be in a state of high liquidity risk. We use a multivariate model allowing to measure correlations between liquidity measures jointly with a state-space model that endogenously defines the illiquid periods.nonouirechercheInternationa
Contagion Analysis In The Banking Sector
No full textThis paper analyses how an external adverse shock will impact the financial situations of banks and insurance companies and how it will diffuse among these companies. In particular we explain how to disentangle the direct and indirect (contagion) effects of such a shock, how to exhibit the contagion network and how to detect the ”superspreaders”, i.e. the most important firms involved in the contagion process. This method is applied to a network of 8 large European banks in order to analyze whether the revealed interconnections within these banks differ depending on the underlying measure of banks’ financial positions, namely their market capitalization, the price of the CDS contract written on their default and their book value.nonouirechercheInternationa
Des femmes et des réseaux : mentoring et réseaux affinitaires au service de l’égalité
No full textLa persistance du plafond de verre dans les entreprises françaises tient au cumul de résistances sociales et organisationnelles (effets de structure) et de freins relationnels (effets de réseau) qui entravent, limitent et retardent l’insertion professionnelle et l’avancement des femmes-cadres. Ces barrières créent des distorsions systémiques à caractère sexiste qui nuisent à l’épanouissement personnel et professionnel ainsi qu’au bien-être au travail des cadres-femmes, tout autant qu’elles peuvent affecter la performance globale des organisations. Au final, elles favorisent la perpétuation et la reproduction d’inégalités sociales sur base genrée.Cet article se penche sur les freins relationnels faisant offense à la progression méritocratique des cadres-femmes au sein des entreprises françaises. Il esquisse des propositions managériales destinées à favoriser le franchissement du plafond de verre, centrées sur le développement de dispositifs organisationnels à substrat relationnel, tels le mentoring et les réseaux affinitaires.The persistency of the glass ceiling in French organizations is produced by the accumulation of societal and organizational resistances (structure effect) and of relational bias. It hampers, limits and delays women’s professional insertion and career advancement. These barriers create some sexist systemic distortions, which harm women’s personal and professional blooming and affect their well-being at work. Furthermore, they can affect the overall performance of the organizations and eventually support the perpetuation and the reproduction of gender-based social inequalities.This paper addresses the relational bias (network effect) obstructing the meritocratic progression of women managers in the French companies. It draws several managerial propositions, aimed to sustain the overtaking of the glass ceiling, enlightening the strategic role of relationally-based organizational initiatives, such as mentoring and affinity networks development.nonouirechercheNationa
Journalistes free-lance et pigistes, deux types de relation d’emploi ?
No full textnonouirechercheNationa
Consumption Growth and Spatial Poverty Traps: An Analysis of the Effect of Social Services and Community Infrastructures on Living Standards in Rural Peru
No full textWhy are there areas with persistenly low levels of income or consumption? This could result from the concentration of households with a low capital endowment or from variations in households’ environment. Peru is a country with a very much fragmented topography and climate, that combines dry deserts, high mountains and rain forest. One important question is to assess the weight of the geographic endowment in the growth process. If differences in geographic endowment matter more than those in households’ characteristics, then encouraging migration to better endowed regions might be a good development policy whereas, in the opposite, it might be better to invest in households’ capital. Of course several factors, either geographic or not, can combine to explain persistent poverty in a given area. In this chapter we test the effect of local geographic endowment of capital on household growth in living standards in rural Peru, using a four years unbalanced panel data set. Our theoretical model of household consumption growth allows for the effect of community variables to modify the returns to augmented capital in the household production function. Three different sources of data are used: the ENAHO 1997-2000 households surveys, the population census of 1993 and the district infrastructure census of 1997. Altogether the addition of these different data sources makes an unusually rich data set, at least when considered with developing country standards. As in Jalan and Ravallion (2002), we use a quasi-differencing method to identify the impact of locally determined geographic and socioeconomic variables, while removing unobserved household and community level fixed effects. GMM are then used to estimate the model parameters. Several significant interesting results appear, showing that private consumption growth depends on local geographic variables, but more on local endowments of private and public assets than on pure geographic characteristics. This suggests to combine policies focused on private and public asset endowments that will reinforce local positive externalities, with infrastructure investments that will help poor households to take advantage of growth opportunities, offered by more dynamic markets across local communities.nonouirechercheInternationa
Utilisation identitaire des dispositifs de contrôle par les membres d’un groupe professionnel : le cas des acheteurs
No full textnonouirechercheInternationa
Counterproductive environmental performance displays : Lessons from the automotive sector
No full textUsing classical models of information processing and persuasion, this study examines the efficiency of European Directive 1999/94/EC, pertaining to automotive carbon emission information, as a means to encourage more sustainable consumption patterns. The Directive requires European carmakers to display their vehicles’ carbon emissions prominently in advertisements. An experiment conducted with a representative sample of consumers reveals that this obligation is counterproductive among non-expert consumers. The display of environmental information might have better effects if it were to use a color-coded grading scale to help them. Beyond this recommendation, the authors discuss some implications for public policy makers.nonouirechercheInternationa