Publications
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.
Objective To evaluate the impact of infertility and Medically Assisted Reproduction (MAR) throughout all aspects of life among infertile women and men. Materials and methods An online survey included 1 045 French patients (355 men, 690 women) who were living or had lived the experience of infertility and MAR. The questionnaire included 56 questions on several domains: global feelings, treatment burden, rapport with medical staff, psychosocial impact, sexual life and professional consequences. Results Respondents had experienced an average of 3.6 (95% CI: 3.3–3.9) MAR cycles: 5% (n = 46) were pregnant, 4% (n = 47) were waiting to start MAR, 50% (n = 522) succeeded in having a live birth following MAR, 19% (n = 199) were currently undergoing ART, and 21% (n = 221) dropped out of the MAR process without a live birth. Satisfaction rates regarding the received medical care were above 80%, but 42% of patients pointed out the lack of information about non-medical support. An important impact on sexual life was reported, with 21% of patients admitted having not had intercourse for several weeks or even several months. Concerning the impact on professional life, 63% of active workers currently in an MAR program (n = 185) considered that MAR had strong repercussions on the organization of their working life with 49% of them reporting a negative impact on the quality of their work, and 46% of them reporting the necessity to lie about missing work during their treatment. Conclusion Despite a high overall level of satisfaction regarding medical care, the burden of infertility and MAR on quality of life is strong, especially on sexuality and professional organization. Clinical staff should be encouraged to develop non-medical support for all patients at any stage of infertility treatment. Enterprises should be warned about the professional impact of infertility and MAR to help their employees reconcile personal and professional life.
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.
We consider an overlapping generations economy in which agents differ through their ability to procreate. Ex-ante infertile households may incur health expenditure to increase their chances of parenthood. This health heterogeneity generates welfare inequalities that deserve to be ruled out. We explore three different criteria of social evaluation in the long-run: the utilitarian approach, the ex-ante egalitarian criterion and the ex-post egalitarian one. We propose a set of economic instruments to decentralize each solution. To correct for the externalities and health inequalities, both a preventive (a taxation of capital) and a redistributive policy are required. We show that a more egalitarian allocation is associated with higher productive investment but reduced health expenditure and thus, lower population growth.
Around 50% of individuals obtain or hear about jobs through social networks. This hiring trend may become problematic when the labor market is tight and people need less social contacts to find a job. Using a one-period static model where network members may receive job offers directly from the firm or indirectly through employed members in the network we show that the share of new hires finding a job through social connections (ie network matching rate) decreases with the job finding rate. Using French data for the period 2003-2012, we test this prediction with immigrants, a population subgroup for whom networks play a major role in occupational decisions. We propose two network matching rate indicators, one based on direct recommendations and another one internalizing the positive externality on the employment probability induced by peers. We find a decreasing relationship between the network matching rate and the job finding rate. Social connections are less helpful for finding jobs during economic expansions.
