Publications

La plupart des informations présentées ci-dessous ont été récupérées via RePEc avec l'aimable autorisation de Christian Zimmermann
Des impacts sanitaires du changement climatique déjà bien visibles : l’exemple des canicules:Journal articleLucie Adélaïde, Olivier Chanel et Mathilde Pascal, Annales des Mines - Responsabilité et environnement, Volume N° 106, Issue 2, pp. 42-47, 2022
Ekeland variational principle on quasi-weighted graphs: improving the work–family balanceJournal articleM. R. Alfuraidan, M. A. Khamsi et A. Soubeyran, Journal of Fixed Point Theory and Applications, Volume 25, Issue 1, pp. 29, 2022

We prove a new minimization theorem in weighted graphs endowed with a quasi-metric distance, which improves the graphical version of the Ekeland variational principle discovered recently (Alfuraidan and Khamsi in Proc Am Math Soc 147:5313–5321, 2019). As a powerful application in behavioral sciences, we consider how to improve the quality of life in the context of the work–family balance problem, using the recent variational rationality approach of stay and change human dynamics (Soubeyran in Variational Rationality, a Theory of Individual Stability and Change: Worthwhile and Ambidextry Behaviors. Preprint. GREQAM, Aix Marseille University, 2009; Soubeyran in Variational Rationality. The Resolution of Goal Conflicts Via Stop and Go Approach-Avoidance Dynamics. Preprint. AMSE, Aix-Marseille University, 2021).

Promoting socially desirable behaviors through persuasion and commitment: Experimental evidenceJournal articleCécile Bazart, Mathieu Lefebvre et Julie Rosaz, Journal of Behavioral and Experimental Economics, Volume 101, pp. 101931, 2022

Through a series of experiments, this paper tests the relative efficiency of persuasion and commitment schemes to increase and sustain contribution levels in a Voluntary Contribution Game. The design allows us to compare a baseline consisting of a repeated public good game to four treatments of the same game in which we successively introduce a persuasion message, commitment devices, and communication between subjects. Our results suggest that these non-monetary procedures significantly increase cooperation and reduce the decay of contributions across periods.

General practitioners' attitude towards cooperation with other health professionals in managing patients with multimorbidity and polypharmacy: A cross-sectional studyJournal articleHélène Carrier, Anna Zaytseva, Aurélie Bocquier, Patrick Villani, Martin Fortin et Pierre Verger, European Journal of General Practice, Volume 28, Issue 1, pp. 109-117, 2022

Background:
Cooperation between general practitioners (GPs) and other healthcare professionals appears to help reduce the risk of polypharmacy-related adverse events in patients with multimorbidity.
Objectives:
To investigate GPs profiles according to their opinions and attitudes about interprofessional cooperation and to study the association between these profiles and GPs’ characteristics.
Methods:
Between May and July 2016, we conducted a cross-sectional survey of a panel of French GPs about their management of patients with multimorbidity and polypharmacy, focussing on their opinions on the roles of healthcare professionals and interprofessional cooperation. We used agglomerative hierarchical cluster analysis to identify GPs profiles, then multivariable logistic regression models to study their associations with the characteristics of these doctors.
Results:
1183 GPs responded to the questionnaire. We identified four profiles of GPs according to their declared attitudes towards cooperation: GPs in the ‘very favourable’ profile (14%) were willing to cooperate with various health professionals, including the delegation of some prescribing tasks to pharmacists; GPs in the ‘moderately favourable’ profile (47%) had favourable views on the roles of health professionals, with the exception for this specific delegation of the task; GPs from the ‘selectively favourable’ profile (27%) tended to work only with doctors; GPs from the ‘non-cooperative’ profile (12%) did not seem to be interested in cooperation. Some profiles were associated with GPs’ ages or participation in continuing medical education.
Conclusion:
Our study highlights disparities between GPs regarding cooperation with other professionals caring for their patients and suggests ways to improve cooperation.

When the messenger is more important than the message: an experimental study of evidence use in francophone AfricaJournal articleAmandine Fillol, Esther McSween-Cadieux, Bruno Ventelou, Marie-Pier Larose, Ulrich Boris Ngue Kanguem, Kadidiatou Kadio, Christian Dagenais et Valéry Ridde, Health Research Policy and Systems, Volume 20, Issue 1, pp. 57, 2022

Background:
Epistemic injustices are increasingly decried in global health. This study aims to investigate whether the source of knowledge influences the perception of that knowledge and the willingness to use it in francophone African health policy-making context.
Methods:
The study followed a randomized experimental design in which participants were randomly assigned to one of seven policy briefs that were designed with the same scientific content but with different organizations presented as authors. Each organization was representative of financial, scientific or moral authority. For each type of authority, two organizations were proposed: one North American or European, and the other African.
Results:
The initial models showed that there was no significant association between the type of authority or the location of the authoring organization and the two outcomes (perceived quality and reported instrumental use). Stratified analyses highlighted that policy briefs signed by the African donor organization (financial authority) were perceived to be of higher quality than policy briefs signed by the North American/European donor organization. For both perceived quality and reported instrumental use, these analyses found that policy briefs signed by the African university (scientific authority) were associated with lower scores than policy briefs signed by the North American/European university.
Conclusions:
The results confirm the significant influence of sources on perceived global health knowledge and the intersectionality of sources of influence. This analysis allows us to learn more about organizations in global health leadership, and to reflect on the implications for knowledge translation practices.

When Is Product Personalization Profit-Enhancing? A Behavior-Based Discrimination ModelJournal articleDidier Laussel et Joana Resende, Management Science, Volume 68, Issue 12, pp. 8872-8888, 2022

This paper investigates duopoly competition when horizontally differentiated firms are able to make personalized product-price offers to returning customers, within a behavior-based discrimination model. In the second period, firms can profile old customers according to their preferences, selling them targeted products at personalized prices. Product-price personalization (PP) allows firms to retain all old customers, eliminating second-period customer poaching. The overall profit effects of PP are shown to be ambiguous. In the second period, PP improves the matching between customers’ preferences and firms’ offers, but firms do not make any revenues in the rival’s turf. In the Bertrand outcome, second-period profits only increase for both firms if the size of their old turfs are not too different or initial products are not too differentiated. However, the additional second-period profits may be offset by lower first-period profits. PP is likely to increase firms’ overall discounted profits when consumers’ (firms’) discount factor is low (high) and firms’ initial products are exogenous and sufficiently different. When the location of initial products is endogenous, profits are hurt because of an additional location (strategic) effect aggravating head-to-head competition in the first period. Likewise, when a fraction of active consumers conceals their identity, PP increases second-period profits at the cost of aggressive first-period price competition. Finally, we show that the room for profitable PP enlarges considerably if firms rely on PP as an effective device to sustain tacit collusive outcomes, with firms credibly threatening to respond to first-period price deviations with second-period aggressive relocations of their standard products.

This paper was accepted by Matthew Shum, marketing.

The environmental justice implications of the Paris low emission zone: a health and economic impact assessmentJournal articleErika Moreno, Lara Schwartz, Sabine Host, Olivier Chanel et Tarik Benmarhnia, Air Quality, Atmosphere & Health, Volume 15, Issue 12, pp. 2171-2184, 2022

Background:
Reducing the mortality burden associated with urban air pollution constitutes a public health priority, and evidence of unequal exposure and susceptibility across population subgroups is growing. Many European countries have implemented low emission zones (LEZs) in densely populated city centers. Although LEZs decrease air pollution exposure and health impacts, evidence is lacking on their impact across neighborhoods and socio-economic groups.
Objectives:
The aim of this study was to evaluate the most equitable approach to implementing the second phase of the LEZ in Paris, France. We also present a literature review of the studies evaluating the benefits associated with LEZs in Europe.
Methods:
A health impact assessment (HIA) was conducted to quantify changes in air pollution exposure and expected health benefits by socioeconomic group and neighborhood related to four hypothetical scenarios for the second phase of the LEZ based on French Deprivation Index scores. The study focused on NO2 and PM2.5 as air pollutants and evaluated the impact of the LEZ on the inequitable burden of childhood asthma and all-cause premature adult mortality. We also conducted an economic evaluation associated with the LEZ benefits on prevented deaths and asthma cases.
Results:
The scenario with the largest LEZ perimeter and the most stringent vehicle standards prevented the highest number of cases and produced the most equitable distribution of health benefits, especially childhood asthma. It is expected that 810 deaths and 3200 cases of asthma could be prevented from the LEZ extension in this scenario. These results were distributed heterogeneously across three socioeconomic (SES) groups, most noticeably with asthma cases as 230, 180, and 210 cases were avoided per 100,000 inhabitants in high, medium, and low SES groups, respectively. We found substantial economic benefits associated with LEZ, with estimates ranging from €0.76 billion to €2.36 billion for prevented deaths. The benefits associated with asthma reduction ranged from €2.3 million to €8.3 million.
Discussion:
Conducting HIAs with a focus on equity will further inform policy makers of the impact of LEZ models on air pollution, health, and environmental justice. Developing these systematic methods and applying them to future LEZs and other air pollution policies will increase their effectiveness to reduce the burden of ambient air pollution on society and the environment.

United, can we be stronger? Did French general practitioners in multi-professional groups provide more chronic care follow-up during lockdown?Journal articleAnna Zaytseva, Pierre Verger et Bruno Ventelou, BMC Health Services Research, Volume 22, Issue 1, pp. 519, 2022

Background:
Given the importance of the continuous follow-up of chronic patients, we evaluated the performance of French private practice general practitioners (GPs) practicing in multi-professional group practices (MGP) regarding chronic care management during the first Covid-19 lockdown in Spring 2020 compared to GPs not in MGP. We consider two outcomes: continuity of care provision for chronic patients and proactivity in contacting these patients.
Methods:
The cross-sectional web questionnaire of 1191 GPs took place in April 2020. We exploit self-reported data on: 1) the frequency of consultations for chronic patients during lockdown compared to their "typical" week before the pandemic, along with 2) GPs' proactive behaviour when contacting their chronic patients. We use probit and bivariate probit models (adjusted for endogeneity of choice of engagement in MGP) to test whether GPs in MGP had significantly different responses to the Covid-19 crisis compared to those practicing outside MGP.
Results:
Out of 1191 participants (response rate: 43.1%), around 40% of GPs were female and 34% were younger than 50 years old. Regression results indicate that GPs in MGP were less likely to experience a drop in consultations related to complications of chronic diseases (- 45.3%). They were also more proactive (+ 13.4%) in contacting their chronic patients compared to their peers practicing outside MGP.
Conclusion:
We demonstrate that the MGP organisational formula was beneficial to the follow-up of patients with chronic conditions during the lockdown; therefore, it appears beneficial to expand integrated practices, since they perform better when facing a major shock. Further research is needed to confirm the efficiency of these integrated practices outside the particular pandemic setup.

Business Training with a Better-Informed Lender: Theory and Evidence from Microcredit in FranceJournal articleRenaud Bourlès, Anastasia Cozarenco, Dominique Henriet et Xavier Joutard, Annals of Economics and Statistics, Issue 148, pp. 65-108, 2022

In the microfinance sector, experienced lenders enjoy an information advantage over first-time entrepreneurs. Our study proposes an analysis of the business training provided on a par with microloans and its potential effect on borrowers’behavior. First, we present a simple theoretical mechanism showing that an information advantage concerning borrower risk can lead to a non-monotonic relationship between risk and business training provision. Second, using a hand-collected data set of loan applications to a French MFI, we empirically examine the relationship between business training provision and borrower risk, controlling for selection bias and endogeneity. The collected evidence supports the existence of a non-monotonic relationship and shows that business training significantly increases the survival time of loans. Our results are robust to alternative econometric models.

How does the exchange-rate regime affect dual-listed share price parity? Evidence from China’s A- and H-share marketsJournal articleJoseph K. W. Fung, Eric Girardin et Jian Hua, Journal of International Money and Finance, Volume 129, pp. 102738, 2022

This paper examines the impact of exchange-rate regime change on the price disparity of China’s dual-listed stocks. We use four years of synchronous intraday data of 26 pairs of dual-listed RMB-denominated A-shares and their corresponding HKD-denominated H-shares. The sample period covers the 2005 and 2008 changes in the exchange rate regime. During that time, the Chinese authorities strictly prohibited short selling of stocks and tightly regulated capital flows. In contrast to the existing general findings, we find that the law of one price can be strengthened for dual-listed stocks (DLSs) in segmented capital markets under a flexible exchange rate regime; the disparity between the DLSs is reduced under the managed float compared to the pegged regime. Moreover, we find that the magnitude of the H-share discount is positively related to the expected RMB appreciation under managed float; however, under the pegged regime the relationship is negative.