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Why consumers react differently to brand transgressions: Functional vs. ethical breaches and psychological contracts
No full textFNEGE 3, ABS 2International audienceBrand transgressions are increasingly common, but their effects on consumer behavior remain inconsistent. While some incidents lead to negative word-of-mouth without affecting sales, others cause a decline in purchasing behavior. Existing literature does not fully explain the divergence in consumer responses. This study investigates how consumers react to functional versus ethical brand transgressions through the lens of psychological contract theory. Drawing on a survey of 862 participants and using structural equation modeling, we examine the mechanisms underlying consumer reactions to breaches of brand promises. Our findings identify two mechanisms: withdrawal, primarily triggered by functional breaches, and indignation, associated with ethical breaches that generate negative word-of-mouth. This research expands psychological contract theory beyond functional failures and demonstrates its relevance in ethical contexts. The results underscore the importance of understanding how consumers interpret a transgression and of tailoring brand responses accordingly
Riemannian adversarial attacks on Symmetric Positive Definite matrices
No full textInternational audienceIn this paper, we study adversarial vulnerabilities when inputs lie on the manifold of symmetric positive definite (SPD) matrices by proposing a Riemannian Projected Gradient Descent (R-PGD) attack. This attack performs updates along the affine-invariant geometry and projects using a geodesic budget. We also give a reconstruction procedure that maps adversarial SPD matrices back to the original signals while enforcing spectral constraints. On Brain Computer Interface datasets and SPDNet, R-PGD is more effective than Euclidean PGD and yields geometrically tailored perturbations that remain adversarial after pre-processing. Our results motivate robustness analyses and defenses for manifold deep models
Fairness in Cooperative Multi-objective Multi-agent Reinforcement Learning using Expected Utility
No full textInternational audienceFairness as equity and compromise across multiple viewpoints is a necessary consideration in any kind of decision that is evaluated from several possibly conflicting perspectives. It is also a property that artificial decision-making agents should uphold to be deployable to real-world problems. However, existing work in sequential decision-making ensures fairness among agents or objectives but struggles with real-world problems that are both multi-agent and multi-objective. Furthermore, research integrating fairness into Multi-Objective Reinforcement Learning (MORL) is focused on optimizing the Scalarized Expected Return (SER) criterion while mostly ignoring the Expected Scalarized Return criterion (ESR). We argue that fairness in MORL should also be investigated under ESR since sometimes it is more suitable when solving problems where fairness matters. In this paper, we study objective-wise fairness in cooperative multi-agent multi-objective decision-making under ESR. We propose the first algorithm that learns efficient decentralized policies while enforcing fairness across objectives under ESR. We identify a key challenge in this setting related to policy conditioning on accumulated returns which hinders decentralized learning and execution, and we present an approach to address it based on inter-agent communication. Experiments on discrete and continuous control tasks demonstrate that our method outperforms existing baselines
Évaluation de l’impact du projet PILAEP 2 dans les quartiers périphériques de Kinshasa (RDC)
No full textIn the Democratic Republic of Congo (DRC), only a third of the population has basic access to drinking water. The lack of access to drinking water is particularly marked in urban areas, especially in the capital city of Kinshasa and its outlying districts. This results in poor hygiene and sanitation conditions and in large amounts of time spent every day for collecting water. To improve this situation, AFD initiated the PILAEP "Promotion de modalités Innovantes pour L'Accès à I'Eau Potable" (2008-2012) and PILAEP2 (2017-2021) projects, which involve setting up autonomous drinking water distribution networks for people living in the outlying districts of Kinshasa and Bas Congo who are not served by the national water distribution company (REGIDESO). Each network is managed by a Users' Association (ASUREP) and comprises a borehole, a reservoir, a distribution network and a system of standpipes, capable of supplying 1,000 inhabitants with drinking water. This report presents the impact assessment of the PILAEP2 project. The first section describes the evaluation protocol and the survey methods used to measure the project's impact. The second section presents descriptive analyses of the study districts, their demographic dynamics and changes in water supply and demand over the study period. The third section presents the results of the evaluation of the impact of the PILAEP 2 project on the populations targeted by the project, focusing on five groups of indicators: water supply, physical and mental health, education, employment and governance.En République Démocratique du Congo (RDC), seul un tiers de la population bénéficie d'un accès basique à l'eau potable. Le manque d’accès à l’eau potable est particulièrement criant en ville, et notamment dans la capitale Kinshasa et ses quartiers périphériques, ce qui se traduit par des conditions d'hygiène et d'assainissement fortement dégradées, auxquelles s'ajoute le poids de la corvée d'eau. Afin d’améliorer cette situation, l’AFD a été à l’initiative des projets PILAEP « Promotion de modalités Innovantes pour L'Accès à I’Eau Potable » (2008-2012) et PILAEP2 (2017-2021) consistant en la mise en place de réseaux autonomes de distribution d’eau potable à destination des populations des quartiers périurbains de Kinshasa et du Bas Congo non desservis par la régie nationale de distribution d’eau (REGIDESO). Chaque réseau est géré par une Association d’Usagers (ASUREP) et se compose d’un forage, d’un réservoir, d’un réseau de distribution et d'un dispositif de bornes-fontaines, susceptibles de pouvoir alimenter en eau potable (payante) 1000 habitants. Le présent rapport restitue le travail d’évaluation de l’impact du projet PILAEP2. La première section décrit le protocole d’évaluation et les dispositifs d’enquête mis en œuvre pour mesurer l’impact du projet. La deuxième section présente des analyses descriptives sur les quartiers de la zone d’étude, leurs dynamiques démographiques et l’évolution de l’offre et de la demande en eau au cours de la période d’étude. La troisième section présente les résultats de l’évaluation de l’impact du projet PILAEP 2 sur les populations ciblées par le projet, en se concentrant sur cinq groupes d’indicateurs : l’approvisionnement en eau, la santé physique et mentale, l’éducation, l’emploi et la gouvernance
International Trade by Production Stage: What’s Real?
No full textThe intensity of global value chains can be proxied by the share of intermediate goods in world trade. This indicator is however affected by price effects, which were particularly strong during the recent inflation episode of the early 2020s. To neutralize these price effects, we compute price deflators by production stage, obtaining series of trade in volume. The deflated series reveal that the share of intermediate goods in world trade is relatively stable since the early 2000s. If anything, trade in parts and components, a key feature of global value chains, seems slightly more dynamic than other production stages. Our results further show that parts and components, as well as capital goods, experienced the fastest trend growth between 2000 and 2023, while primary goods lagged behind. Finally, trade volumes appear strongly procyclical overall, except for primary goods, which display no significant correlation with the global output gap
Why should I comply with taxes if others don’t? Social information and behavioral convergence: An experimental study
No full textInternational audienceThis experimental study investigates the impact of social information about others’ tax behavior on individuals’subsequent tax decisions. Two types of social information are introduced: (i) the average income reportedwithin the subject’s entire group, and (ii) the average income reported within a reference subgroup made ofeither peers or non-peers and chosen by the subject. Our results show that social information significantlyaffects subsequent tax decisions, with a change in reported income ranging from 15% to 30% of total incomeon average. Moreover, the influence of whole-group information on tax behavior appears to be stronger thanthat of chosen-group information. Quite strikingly, a majority of subjects show more interest in the tax behaviorof non-peers than in that of peers. Finally, our data provide strong evidence of behavioral convergence towardsthe average tax behavior of others
Dancing to the wrong tune: How rational myopia, belief heterogeneity, and adjustment costs shape financial bubbles
No full textInternational audienceWe introduce the Anticipations-Based Production Equilibrium (ABPE) as a minimal extension of the Arrow–Radner Production Equilibrium (ARPE). Whereas ARPE requires optimality and rational expectations, ABPE relies only on local optimization and locally coherent expectations. This mild departure preserves internal consistency, coincides with ARPE in discrete time, while in continuous time allows for speculative bubbles, defined intrinsically as price trajectories that rise explosively before collapsing in finite time. To illustrate the concept, we develop a continuous-time production economy with heterogeneous beliefs and convex adjustment costs, where bubbles emerge endogenously from the interplay of nonlinear price dynamics, and belief-driven momentum. We characterize the precise conditions under which bubbles emerge, and distinguish between financial bubbles, which affect only asset prices, and real bubbles, which also impact production and growth. The ABPE framework is general and accommodates a variety of belief formation mechanisms, which we illustrate with anticipations constructed through backward inference and regret minimization
Le retour d'expérience, une contribution à la pédagogie frugale ?
No full textInternational audienceDebriefing sessions (After-Action Review) are working meetings that bring a team together to review a recent, significant experience in order to develop a shared understanding of that experience and learn lessons from it that will improve future collective actions in similar situations. This discipline, initially developed in the military to address significant capacity development challenges, has gradually spread to businesses through several channels and in various formats. Given its proven effectiveness and simplicity of implementation, the question arises as to whether this practice of learning from experience should be extended to management training in order to combine pedagogical effectiveness, frugality of means, and training in metacognition to develop independent thinking, critical thinking, and systemic thinking among students or participants.Le retour d'expérience à chaud est une réunion de travail qui rassemble une équipe dans la perspective de revisiter une expérience récente, et à enjeu, pour faire émerger une compréhension partagée de cette expérience et en tirer des leçons afin d'améliorer des actions collectives futures, dans des situations de nature semblable. Cette discipline, développée initialement dans le monde militaire pour répondre à des enjeux de développement de capacités importants, s'est progressivement répandue dans les entreprises par le biais de plusieurs canaux et dans des formats variés. Au regard de son efficacité avérée et de sa simplicité de mise en œuvre, la question se pose d'élargir cette pratique d'apprentissage de l'expérience aux formations en gestion pour combiner efficacité pédagogique, frugalité des moyens, et entrainement à la méta-cognition au service du développement de l'autonomie de pensée, de l'esprit critique et de la pensée systémique chez les élèves ou participants.</div
(Un)intended consequences: a social sciences stocktake of a decade of Global Action Plan-inspired antimicrobial governance
No full textInternational audienc
Mission accomplished? A post-assessment of EU ETS impact on power sector emissions reduction
No full textInternational audienceThe debate on the capacity of the European Union Emissions Trading System (EU ETS) to effectively induce CO emissions reduction is still ongoing. This is particularly noteworthy in the case of the power sector, where numerous decarbonization policies overlap. This paper contributes to this discussion by leveraging a methodological approach that circumvents the challenges of constructing credible counterfactuals for causal inference and allows for disentangling the impact of the EU ETS from other measures on the power sector’s abatement efforts, alongside influencing factors such as weather. Specifically, we employ a Bayesian structural time series (BSTS) model, conceptually related to synthetic control techniques, to assess the effectiveness of the three completed phases of the EU ETS (2005-2020) in reducing CO emissions in the power sector across 24 Member States. We analyze the policy implementation effect over the course of each phase by comparing actual power sector emissions with counterfactual estimates derived from contemporaneous predictors related to such emissions. The results indicate a statistically significant emissions reduction in the second and third phases, with no significant reduction in the first phase. The power sector’s centrality to the EU ETS, and its critical role in our economies emphasize the importance of our findings in evaluating emissions reduction objectives