Publications
Le monde du travail comme toute la société est en train de vivre des mutations majeures correspondant à un changement de paradigme que nous qualifions de postmoderne. Ce livre analyse la façon dont les relations professionnelles se transforment. Les grilles de lecture actuelles tout comme les modes opératoires ne permettent pas d’appréhender les nouveaux questionnements. Les auteurs proposent une nouvelle grammaire tout autant conceptuelle que pratique pour faire émerger un management différent fondé sur la régulation collégiale.
We investigate empirically, and explain theoretically, how the relative wages of skilled and unskilled workers vary with their relative supplies in open economies. Our results combine the insights of simple labour market and trade models. In countries that trade, relative wages respond inversely to variation in skill supplies, but the response decreases with the degree of openness to trade and is small in very open countries. To reconcile our results with standard estimates of the elasticity of substitution between skilled and unskilled workers, we allow also for the influence of directed technical change and income elasticity of demand for skill-intensive goods.
I develop a model of activism and polarization in the context of electoral competition. Two candidates simultaneously announce policy platforms and seek the support of ideologically inclined activists. Activists compete to influence electoral outcomes by expending costly support for their respective candidates. The presence of activists always moderates the platform choice of candidates, compared to the case of no activism. The central finding of the paper is that the relationship between partisanship of activists and polarization is ambiguous. As activists become increasingly partisan, polarization of candidate platforms reduces or widens depending on the costs of activism. I present normative conditions under which the presence of activism and increased partisanship among activists are both welfare-improving for voters. Finally, introducing a public funding option for candidates increases polarization in the political process.
Face à l’irruption de la Covid-19, ont surgi des demandes urgentes de prédire, d’expliquer et de faire comprendre sa diffusion aussi bien géographique que sociale, notamment lorsqu’il s’agissait de soutenir telle ou telle décision politique ou de santé publique (distanciations, confinement, etc.). Plusieurs modèles computationnels – en particulier à agents – ont été bien vite mis en avant. Mais dans quelle mesure sont-ils réellement à même de remplir de telles fonctions, en particulier dans un contexte aussi contraint et variable ? Ce livre propose un ensemble d’analyses précieuses et salutaires pour qui voudra former son jugement à ce sujet. Il s’appuie sur des exemples et des analyses de plusieurs modèles de diffusion de la Covid-19, dont certains ont été utilisés par les pouvoirs publics. Il propose aussi des modèles alternatifs, dont certains inédits. Il s’adresse à un large lectorat. Les analyses techniques y sont effectuées avec beaucoup de pédagogie, sans sacrifier à la précision. Elles peuvent donc intéresser les concepteurs et utilisateurs de modèles, les étudiants, les élus, les associations concernées et tout citoyen soucieux de comprendre ces outils omniprésents. Au-delà du cas de la Covid-19, on y trouve une mise en perspective et une discussion plus générale concernant l’usage des modèles formels en sciences sociales, en particulier dans le cadre de l’aide à la décision publique. Analysant le contexte de la crise que l’on traverse, les auteurs évitent de donner un point de vue personnel, mais au contraire tentent d’aider chacun à avancer dans sa propre réflexion, en mettant en avant les questionnements qui peuvent s’adosser aux modèles présentés.
L’ouvrage comprend deux parties : l’une qui propose une analyse critique de modèles existants, l’autre prenant la forme de trois propositions de modèles qui permettent de percevoir la richesse et la multiplicité des modèles agents de diffusion de maladie – à la fois dans leur conception et leur manipulation. Un glossaire et un intermède sur les « apports des modèles agents en général et pour la Covid-19 en particulier » replacent ces réflexions dans le cadre plus large de la simulation agents appliquée aux sciences sociales.
This study assesses the effect of an economy’s business environment on the ability of firms to be part of a global value chain (GVC). With the use of a comprehensive firm-level dataset from the World Bank Enterprise Survey—and with a special focus on the countries of the Middle East and North Africa and East Asia and Pacific regions—the contribution of the paper is threefold: First, it provides a range of measures of the characteristics of firms that would identify a firm as likely to be integrated into a GVC. Second, it examines the association between an array of business environment variables—infrastructure; access to finance; fiscal policy; enforcement of contracts; ease of obtaining permits; extent of the informal sector; trade procedures; and firm and investor security—and the likelihood of a firm’s being integrated into a GVC. Third, we examine these effects separately for small and large firms and for sectors with high and low tariffs. Our main findings show that, in general, the number of days that are required to pay taxes, the number of procedures that are necessary to register property, and the time to export and to import have a significantly negative association with the likelihood of a firm’s integration into a GVC. More heterogeneity is observed at the regional level, at the firm size level, and for sectors with high versus low tariffs.
We show that a monopolist's profit is higher if he refrains from collecting coarse information on his customers, sticking to constant uniform pricing rather than recognizing customers' segments through their purchase history. In the Markov perfect equilibrium with coarse information collection, after each commitment period, a new introductory price is offered to attract new customers, creating a new market segment for price discrimination. Eventually, the whole market is covered. Shortening the commitment period results in lower profits. These results sharply differ from the ones obtained when the firm can uncover the exact willingness-to-pay of each previous customer.
Background:
Ageing populations and rising prevalence of non-communicable diseases (NCDs) increasingly contribute to the growing cost burden facing European healthcare systems. Few studies have attempted to quantify the future magnitude of this burden at the European level, and none of them consider the impact of potential changes in risk factor trajectories on future health expenditures.
Methods:
The new microsimulation model forecasts the impact of behavioural and metabolic risk factors on NCDs, longevity and direct healthcare costs, and shows how changes in epidemiological trends can modify those impacts. Economic burden of NCDs is modelled under three scenarios based on assumed future risk factors trends: business as usual (BAU); best case and worst case predictions (BCP and WCP).
Findings:
The direct costs of NCDs in the EU 27 countries and the UK (in constant 2014 prices) will grow under all scenarios. Between 2014 and 2050, the overall healthcare spending is expected to increase by 0.8% annually under BAU. In the all the countries, 605 billion Euros can be saved by 2050 if BCP is realized compared to the BAU, while excess spending under the WCP is forecast to be around 350 billion. Interpretation:
Although the savings realised under the BCP can be substantial, population ageing is a stronger driver of rising total healthcare expenditures in Europe compared to scenario-based changes in risk factor prevalence.
Information provision is a relatively recent but steadily growing environmental policy tool. Its emergency and topicality are due to the current escalation of ecological threats. Meanwhile, its high complexity and flexibility require a comprehensive approach to its design, which has to be tailored for specific characteristics of production process, market structure, and regulatory goals. This work proposes such an approach and builds a framework based on a three-level mathematical program extending well-known two-level Stackelberg game by introducing one more economic agent and one extra level of this sequential game. This study provides simple and very intuitive algorithms to compute optimal multi-tier information provision policies, both mandatory and voluntary. The paper urges for the wide implementation of such efficient environmental policy design tools.
Purpose
To address the gap highlighted in the literature on the effect of professional interventions to facilitate continued employment, this study aims to evaluate the effect of workplace accommodations on the continued employment 5 years after a cancer diagnosis.
Methods
This study is based on VICAN5, a French survey conducted in 2015-2016 to examine the living conditions of cancer survivors 5 years after diagnosis. Two subsamples, one with and one without workplace accommodations, were matched using a propensity score to control for the individual, professional, and medical characteristics potentially associated with receipt of workplace accommodations.
Results
The study sample was composed of 1514 cancer survivors aged 18-54 and employed as salaried at diagnosis. Among them, 61.2% received workplace accommodations within 5 years after diagnosis: 35.5% received a modified workstation, 41.5% received a modified schedule, and 49.2% received reduced hours. After matching, receipt of workplace accommodations appeared to improve the continued employment rate 5 years after cancer diagnosis from 77.8% to 95.0%.
Conclusions
Receipt of workplace accommodations strongly increases the continued employment of cancer survivors 5 years after diagnosis. More research is needed to better understand the differences in receipt of workplace accommodations along with the related selection effect.
