HAL Paris Dauphine-PSL
Not a member yet
21932 research outputs found
Sort by
CONVERGENT POWER SERIES FOR ANHARMONIC CHAIN WITH PERIODIC FORCING
No full textInternational audienceWe study the case of a pinned anharmonic chain of oscillators, with coordinates (q.p) = {(q x , p x ) ∶ x ∈ Z N = {-N, ......, N }}, subjected to an external driving force F(⋅) of period θ = 2π ω acting on the oscillator at x = 0. The system evolves according to a Hamiltonian dynamics with frictional damping, γ > 0, present at both endpoints x = -N, N . The Hamiltonian is given by(0.1) where V (⋅) and U (⋅) are C 2 smooth anharmonic pinning and interaction potentials with bounded second derivatives, ω 0 > 0 and ν ∈ R. We prove that if ω does not fall in the spectrum of the infinite harmonic system I ∶= [ω 0 , ω 2 0 + 4], then there exists a ν 0 > 0 such that for ν < ν 0 the system approaches asymptotically in time a unique θ-periodic solution, whose coordinates are given by a convergent power type series in ν. The series coefficients are bounded and smooth functions of ν. The value of ν 0 is a lower bound on the radius of convergence, independent of N , the friction coefficient γ > 0 and F. It depends only on the supremum norm of V ′′ (⋅) and U ′′ (⋅) and the distance of the set of integer multiplicities of ω from I.</div
Does Merging Small Bankruptcy Courts Increase Their Efficiency?
No full textWe estimate the impact of a 2009 reform that merged small bankruptcy courts on the qualityof their rulings. A conceptual framework enables us to link difference-in-difference estimatesto the impact of the reform on Type 1 errors (restructuring a non-viable firm) and Type 2errors (liquidating a viable firm). We apply this framework to an (almost) exhaustive sampleof 600,000 bankruptcy cases in France that started between 2000 and 2019. The reformunambiguously reduces Type 1 errors while having no impact on Type 2 errors. Post-mergercourt behavior is determined more by that of the absorbing court than by that of theabsorbed one
Do Europeans really feel better at home than in a nursing home?
No full textInternational audienceAbstract The desire to age “in place” avoiding nursing homes (NHs) seems universally acknowledged, and the recent COVID-19 pandemic may have encouraged it. Using data from the Survey of Health Ageing and Retirement in Europe (SHARE), we show that those living in NH declared a lower level of life satisfaction than those living in the community. Controlling for demographics, the difference was around −8% over an average score of 6.73/10. Adding controls for the economic situation, health, and disability level the negative association becomes nonsignificant. Functional status seems to explain most of the difference in well-being between nursing and private homes. However, the selection into NH may be linked to unobservable characteristics. We tackle this causality issue in two ways. First by using propensity score matching methods. Living in an NH becomes associated with lower well-being. Finally, we make use of our longitudinal data to further reduce the potential impact of nonobservables. The conclusions are globally reversed: living in an NH is associated with higher well-being. This is coherent with a model of optimal residential choices: living in an NH might not be desired but proves to be the best choice for those who make it. This article is part of a Special Collection on Cross-National Gerontology
"L’illusion du mauvais choix : coûts d’opportunité et croyance dans la redondance des agents immobiliers"
No full textInternational audiencePurpose This paper examines how digital disintermediation and perceptions of broker usefulness influence homebuyers’ satisfaction in real estate transactions. It introduces the concept of broker redundancy beliefs (BRB) to understand the psychological impact of opportunity costs when buyers choose to work with a broker instead of pursuing a direct transaction (FSBO). Design/methodology/approach A survey of 1,964 French homebuyers was conducted to compare outcomes between brokered and direct transactions. Using moderated mediation models, the study assesses how transaction type influences price satisfaction and recommendation intentions, and how these effects are conditioned by BRB. Findings Results show that buyers using brokers report significantly lower price satisfaction and are less likely to recommend this transaction mode, despite similar purchase prices and shorter search durations. The negative impact is entirely moderated by BRB: when BRB is low, the effect disappears. These results suggest that the perception of opportunity cost—rather than actual outcomes—drives dissatisfaction. Research limitations/implications This study highlights how opportunity cost perceptions and broker redundancy beliefs shape buyer satisfaction, offering a behavioral explanation for persistent skepticism toward brokers. Although based on French data, the mechanisms identified are relevant across markets where digital platforms increase the visibility of FSBO alternatives. The findings imply that brokers must actively demonstrate skills, effort, and ethical conduct to counter redundancy perceptions, while policymakers and platform designers should consider how intermediation is positioned in increasingly digital ecosystems. Limitations such as data timing, response rate uncertainty, and lack of seller perspectives point to fruitful avenues for future research. Practical implications In an AI-enhanced real estate environment, brokers must visibly demonstrate skill and effort to counteract perceptions of redundancy. Younger, digital-native buyers with high BRB represent a critical target for repositioning brokerage value. Emphasizing ethical conduct, transparency, and personalized insight may help rebuild trust. Social implications This research shows that buyer dissatisfaction with brokers is not purely economic but rooted in perceived opportunity costs and redundancy beliefs. Such perceptions may erode trust in professional intermediation and accelerate a shift toward peer-to-peer transactions, reinforcing broader patterns of digital disintermediation in society. The findings highlight the importance of transparency, ethical conduct, and visible value creation in maintaining consumer confidence in intermediaries. They also suggest that without renewed credibility, brokerage risks losing its social legitimacy, particularly among younger and more digitally literate generations, with potential consequences for fairness, accountability, and professionalism in housing markets. Originality/value This study provides a novel psychological explanation for declining buyer satisfaction in brokered transactions, despite equivalent outcomes. It highlights how perceived opportunity cost and cognitive bias influence evaluations of intermediation in real estate.ObjectifCette étude étudie comment la désintermédiation numérique et les perceptions de l’utilité des agents immobiliers influencent la satisfaction des acheteurs dans les transactions immobilières. Elle introduit le concept de croyances en la redondance des agents (CRA) pour analyser l’impact psychologique des coûts d’opportunité lorsque les acheteurs choisissent de recourir à un agent plutôt qu’à une transaction directe (vente entre particuliers, ou FSBO). Le cadre théorique s’appuie sur l’idée que ces croyances modulent la satisfaction perçue, indépendamment des résultats objectifs.MéthodologieUne enquête a été menée auprès de 1 964 acheteurs français pour comparer les résultats des transactions réalisées avec ou sans agent. À l’aide de modèles de médiation modérée, l’étude évalue comment le type de transaction affecte la satisfaction concernant le prix et l’intention de recommander ce mode de transaction, ainsi que le rôle des CRA dans ces relations.RésultatsLes résultats révèlent que les acheteurs ayant utilisé un agent déclarent une satisfaction significativement plus faible concernant le prix et sont moins enclins à recommander ce mode de transaction, malgré des prix d’achat similaires et des durées de recherche plus courtes. Cet effet négatif est entièrement modéré par les croyances CRA : lorsque celles-ci sont faibles, cet impact négatif disparaît. Ces résultats suggèrent que la perception de coûts d’opportunité, plutôt que les résultats effectifs, est le principal moteur de l’insatisfaction.Limites et implications pour la rechercheCette étude met en lumière comment les perceptions des coûts d’opportunité et les croyances en la redondance des agents façonnent la satisfaction des acheteurs, offrant une explication comportementale à la persistance de la méfiance envers les professionnels de l'immobilier. Les mécanismes identifiés sont pertinents pour comprendre les marchés où les plateformes numériques augmentent la visibilité des alternatives FSBO. Les résultats impliquent que les agents doivent démontrer activement leurs compétences, leurs efforts et leur éthique pour contrer les perceptions de redondance. Les limites, telles que le timing des données, l’incertitude sur le taux de réponse et l’absence de perspective des vendeurs, ouvrent des pistes pour de futures recherches.Implications pratiquesDans un environnement immobilier enrichi par l’IA, les agents doivent rendre visibles leurs compétences et leurs efforts pour contrer les perceptions de redondance. Les acheteurs plus jeunes, natifs du numérique et présentant des CRA élevées, constituent une cible critique pour repositionner la valeur du courtage. Mettre l’accent sur l’éthique, la transparence et des conseils personnalisés pourrait contribuer à rétablir la confiance.Implications socialesCette recherche montre que l’insatisfaction des acheteurs envers les agents n’est pas purement économique, mais ancrée dans les perceptions des coûts d’opportunité et des croyances en la redondance. Ces perceptions pourraient éroder la confiance dans l’intermédiation professionnelle et accélérer le passage vers des transactions de pair à pair, renforçant ainsi les tendances plus larges de désintermédiation numérique dans la société. Les résultats soulignent l’importance de la transparence, de l’éthique et de la création de valeur visible pour maintenir la confiance des consommateurs dans les intermédiaires. Sans une crédibilité renouvelée, le courtage risque de perdre sa légitimité sociale, en particulier auprès des générations plus jeunes et plus compétentes numériquement, avec des conséquences potentielles sur l’équité, la responsabilité et le professionnalisme dans les marchés du logement.Originalité et valeurCette étude propose une explication psychologique inédite de la baisse de satisfaction des acheteurs dans les transactions avec agents, malgré des résultats objectifs équivalents. Elle met en lumière comment la perception des coûts d’opportunité et les biais cognitifs influencent l’évaluation de l’intermédiation dans l’immobilier
Cultural Production Reveals Transitions to Sustained Human Development in both European and Non-European Societies
No full textSustained human development is often seen as a recent phenomenon, primarily linked to Europe's Industrial Revolution. This perspective has shaped much of our historical understanding, but it relies on a limited set of economic indicators with restricted temporal and geographic coverage. In this article, we introduce Cultural Production as a complementary proxy for human development, particularly suited to long-term and cross-regional comparisons. Cultural production reflects the extent to which societies enable individuals to acquire knowledge, develop skills, and contribute to intellectual and artistic life-conditions closely tied to education, health, material security, and institutional support. We construct a global dataset tracking 122,634 distinct cultural producers (e.g., scientists, artists, writers) and apply ecological methods to estimate the number of unrecorded figures, correcting for differential survivorship bias. The resulting measure enables a broader and deeper reconstruction of human development across time and space. Our results challenge the prevailing view that meaningful development began only in modern Europe. We confirm that Western Europe experienced continuous gains from the 11th century onward, but we also uncover sustained growth in non-Western regions long before the 19th century. Japan shows multiple developmental phases, including a continuous rise after 1500 CE. In China, we trace human development back over 1,500 years, identifying major advances during the Han, Tang, and late imperial periods. In South and West Asia, we reveal marked progress under the Abbasid Caliphate and the Delhi Sultanate. Cultural Production also enables estimates of human development for Antiquity, showing developmental peaks in Classical Greece and Rome, though these were not sustained. Altogether, our findings suggest that all major regions, including non-European societies, transitioned from stagnation to sustained growth well before the Industrial Revolution-some as early as 1000 CE. These results suggest a more widespread and earlier pattern of human development across civilizations than previously recognized
Self-interacting approximation to McKean-Vlasov long-time limit: a Markov chain Monte Carlo method
No full textInternational audienceFor a certain class of McKean-Vlasov processes, we introduce proxy processes that substitute the mean-field interaction with self-interaction, employing a weighted occupation measure. Our study encompasses two key achievements. First, we demonstrate the ergodicity of the self-interacting dynamics, under broad conditions, by applying the reflection coupling method. Second, in scenarios where the drifts are negative intrinsic gradients of convex mean-field potential functionals, we use entropy and functional inequalities to demonstrate that the stationary measures of the self-interacting processes approximate the invariant measures of the corresponding McKean-Vlasov processes. As an application, we show how to learn the optimal weights of a two-layer neural network by training a single neuron
Ancestral Meanings: a prelude to evolutionary animal linguistics
No full textInternational audienceHow did the very first meaning components arise in animals? We argue that answers interact in interesting ways with data on current and ancestral animal communication systems. Using standard notions of evolutionary stability in biology, we develop a simple framework to analyze the emergence of three meaning components: individual signals, non-trivial combinations, and pragmatic principles of competition among signals. We show that for elementary signals to arise, they should have null cost, or be understood from the start. While this conclusion dovetails with the traditional idea that signals often originate in cues, i.e. informative by-products of noncommunicative processes, the two scenarios (null cost vs. understanding from the start) can be distinguished in case studies involving ancestral meaning reconstruction. For non-trivial combinations of the form CC' (such as pyow-hack sequences in putty-nosed monkeys and ABC-D sequences in Japanese tits), we show that their emergence is heavily constrained because they should initially give rise to some miscommunication, as CC' could also be understood as the (trivial) combination of separate utterances C and C'. Finally, we investigate the evolution of two pragmatic principles that were posited in recent animal linguistics: the Informativity Principle and the Urgency Principle. We argue that both have a clear evolutionary path, especially if they start appearing in production, and then in comprehension. Overall, recent work in animal linguistics can be fruitfully combined with simple principles of evolutionary stability and with ancestral signal reconstruction to address in a precise fashion questions about the very first meaning operations in nature
Deep trade agreements and international migration: the role of visa provisions
No full textInternational audienceAn increasing number of regional trade agreements contains provisions that ease access to visas among member countries, which reduces the administrative cost of crossing the border. Combining United Nations data on bilateral stocks of immigrants in the period 1990–2020 with World Bank data on the content of 279 regional trade agreements, this article presents robust evidence of a positive effect of visa provisions in regional trade agreements on bilateral migration: the presence of visa provisions in regional trade agreements increases the bilateral stock of immigrants by 5.8 per cent. This result is robust to an instrumental variable strategy addressing the endogeneity problem. The effect of the inclusion of visa provisions in regional trade agreements is particularly effective among country pairs with different income levels (such as North-South). For this type of country pairs, the presence of visa provisions in regional trade agreements increases the bilateral stock of immigrants by 12.7 per cent. Finally, the article shows that the effectiveness of visa provisions in regional trade agreements reduces with the anti-immigration sentiment of voters in the destination
