Publications

La plupart des informations présentées ci-dessous ont été récupérées via RePEc avec l'aimable autorisation de Christian Zimmermann
The effect of international accreditations on students’ revealed preferences: Evidence from French Business schoolsJournal articleJulien Jacqmin et Mathieu Lefebvre, Economics of Education Review, Volume 85, pp. 102192, 2021

This paper evaluates how three different international accreditations for business schools (AACSB, EQUIS and AMBA) affect student preferences, expressed via enrollment decisions. Focusing on the French context, we build a relative preference indicator to compare schools using data collected by the central clearinghouse that allocates students to schools. We observe that all three accreditations positively and significantly influence students, but that the impact of the AACSB accreditation is larger than the other two accreditations. Having an AACSB accreditation is equivalent to moving up four places in rankings by L’étudiant magazine, whereas the impact of having EQUIS or AMBA is similar to moving up two places. We also find a sizeable “triple crown” effect, meaning that the three accreditations tend to complement each other. Our results are robust to different ways of assessing potential self-selection into accreditation.

Economic Aspects of Settlement in the Oasis of Bukhara, Uzbekistan: An Archaeo-Economic ApproachJournal articleRocco Rante et Federico Trionfetti, Cambridge Archaeological Journal, Volume 31, Issue 4, pp. 581-596, 2021

This paper focuses on the new approach studying variations in city size and the impact that the Silk Road had on the structure of cities, demonstrated through the study of economic aspects of the Bukhara oasis. We use archaeological data, compare the ancient economy to modern ones, use modern economic theory and methods to understand ancient society, and use what we have learned about the ancient economy to understand modern economies better. In sum, we explore the past through the present and the latter through the former. Our main finding is the generation of models able to answer to the city-size distribution in different territories, comparing them between the past and the present. This study first revealed that, through Zipf's Law, we found similarities between modern post-Industrial Revolution and medieval economics. Secondly, we also found that in ancient times the structure of the city was linked with the local economic demand. We have demonstrated this through the study of cities along the Silk Road.

Integrating HIV services and other health services: A systematic review and meta-analysisJournal articleCaroline A. Bulstra, Jan A. C. Hontelez, Moritz Otto, Anna Stepanova, Erik Lamontagne, Anna Yakusik, Wafaa M. El-Sadr, Tsitsi Apollo, Miriam Rabkin, UNAIDS Expert Gro Integration, et al., PLOS Medicine, Volume 18, Issue 11, pp. e1003836, 2021

Background
Integration of HIV services with other health services has been proposed as an important strategy to boost the sustainability of the global HIV response. We conducted a systematic and comprehensive synthesis of the existing scientific evidence on the impact of service integration on the HIV care cascade, health outcomes, and cost-effectiveness.

Methods and findings
We reviewed the global quantitative empirical evidence on integration published between 1 January 2010 and 10 September 2021. We included experimental and observational studies that featured both an integration intervention and a comparator in our review. Of the 7,118 unique peer-reviewed English-language studies that our search algorithm identified, 114 met all of our selection criteria for data extraction. Most of the studies (90) were conducted in sub-Saharan Africa, primarily in East Africa (55) and Southern Africa (24). The most common forms of integration were (i) HIV testing and counselling added to non-HIV services and (ii) non-HIV services added to antiretroviral therapy (ART). The most commonly integrated non-HIV services were maternal and child healthcare, tuberculosis testing and treatment, primary healthcare, family planning, and sexual and reproductive health services. Values for HIV care cascade outcomes tended to be better in integrated services: uptake of HIV testing and counselling (pooled risk ratio [RR] across 37 studies: 1.67 [95% CI 1.41–1.99], p < 0.001), ART initiation coverage (pooled RR across 19 studies: 1.42 [95% CI 1.16–1.75], p = 0.002), time until ART initiation (pooled RR across 5 studies: 0.45 [95% CI 0.20–1.00], p = 0.050), retention in HIV care (pooled RR across 19 studies: 1.68 [95% CI 1.05–2.69], p = 0.031), and viral suppression (pooled RR across 9 studies: 1.19 [95% CI 1.03–1.37], p = 0.025). Also, treatment success for non-HIV-related diseases and conditions and the uptake of non-HIV services were commonly higher in integrated services. We did not find any significant differences for the following outcomes in our meta-analyses: HIV testing yield, ART adherence, HIV-free survival among infants, and HIV and non-HIV mortality. We could not conduct meta-analyses for several outcomes (HIV infections averted, costs, and cost-effectiveness), because our systematic review did not identify sufficient poolable studies. Study limitations included possible publication bias of studies with significant or favourable findings and comparatively weak evidence from some world regions and on integration of services for key populations in the HIV response.

Conclusions
Integration of HIV services and other health services tends to improve health and health systems outcomes. Despite some scientific limitations, the global evidence shows that service integration can be a valuable strategy to boost the sustainability of the HIV response and contribute to the goal of ‘ending AIDS by 2030’, while simultaneously supporting progress towards universal health coverage.

Evidence-based policymaking when evidence is incomplete: The case of HIV programme integrationJournal articleJan A. C. Hontelez, Caroline A. Bulstra, Anna Yakusik, Erik Lamontagne, Till W. Bärnighausen et Rifat Atun, PLOS Medicine, Volume 18, Issue 11, pp. e1003835, 2021

Jan Hontelez and co-authors discuss the use of different types of evidence to inform HIV program integration.

Vers une couverture sanitaire universelle au Sénégal : quelles sont les meilleures stratégies de financement ?Journal articleSameera Awawda, Mohammad Abu-Zaineh et Bruno Ventelou, Revue internationale des études du développement, Issue 247, pp. 37-60, 2021

Cette étude a pour objectif d’évaluer différents modes de financement de la couverture santé universelle au Sénégal. La méthode utilisée, la micro-simulation, permet d’examiner l’impact de différents scenarii sur les consommations des ménages ainsi que sur les dépenses publiques. Les résultats montrent que la généralisation d’une assurance-maladie à l’ensemble de la population, associée à une réduction des coûts directs des soins, augmenterait les consommations de soins des Sénégalais, améliorant donc leur accès aux services de santé. Néanmoins, une telle généralisation serait coûteuse pour les finances publiques. Pour limiter les coûts supportés par le gouvernement, l’augmentation du taux d’imposition sur la consommation et de la prime de contribution à l’assurance-maladie serait utile et permettrait de ramener les finances publiques à l’équilibre.

Physicians’ incentives to adopt personalised medicine: Experimental evidenceJournal articleDavid Bardey, Samuel Kembou et Bruno Ventelou, Journal of Economic Behavior & Organization, Volume 191, pp. 686-713, 2021

We study physicians’ incentives to use personalised medicine techniques, replicating the physician’s trade-offs under the option of personalised medicine information. In a laboratory experiment conducted in two French Universities, prospective physicians played a real-effort game. We vary both the information structure (free access versus paid access to personalised medicine information) and the payment scheme (pay-for-performance (P4P), capitation (CAP) and fee-for-service (FFS)), implementing a within-subject design. Our results are threefold: (i) Compared to FFS and CAP, the P4P scheme strongly and positively impacts the decision to adopt personalised medicine. (ii) Although expected to dominate the other schemes, P4P is not always efficient in transforming free access to personalised medicine into higher quality of care. (iii) When it has to be paid for and after controlling for self-selection, personalised medicine is positively associated with quality, suggesting that subjects tend to make better use of information that comes at a cost. We find this effect to be stronger for males than for females prospective physicians. Quantification of our results however suggests that this positive impact is not strong enough to justify generalising the payment for personalised medicine access. Finally, we develop a theoretical model that includes in its set-up a commitment device component, which is the mechanism that we inferred from the data of the experiment. Our model replicates the principal results of the experiment, reinforcing the interpretation that the higher quality provided by subjects who bought personalised medicine can be interpreted as a commitment device effect.

Air pollution in an urban world: A global view on density, cities and emissionsJournal articleDavid Castells-Quintana, Elisa Dienesch et Melanie Krause, Ecological Economics, Volume 189, pp. 107153, 2021

In this paper, we take a global view at air pollution looking at cities and countries worldwide. We pay special attention at the spatial distribution of population and its relationship with the evolution of emissions. To do so, we build i) a unique and large dataset for more than 1200 (big) cities around the world, combining data on emissions of CO2 and PM2.5 with satellite data on built-up areas, population and light intensity at night at the grid-cell level for the last two decades, and ii) a large dataset for more than 190 countries with data from 1960 to 2010. At the city level, we find that denser cities show lower emissions per capita. We also find evidence for the importance of the spatial structure of the city, with polycentricity being associated with lower emissions in the largest urban areas, while monocentricity being more beneficial for smaller cities. In sum, our results suggest that the size and structure of urban areas matters when studying the density-emissions relationship. This is reinforced by results using our country-level data where we find that higher density in urban areas is associated with lower emissions per capita. All our main findings are robust to several controls and different specifications and estimation techniques, as well as different identification strategies.

Controlling monopoly power in a double-auction market experimentJournal articleGiuseppe Attanasi, Kene Boun My, Andrea Guido et Mathieu Lefebvre, Journal of Public Economic Theory, Volume 23, Issue 5, pp. 1074-1101, 2021

There is robust evidence in the experimental economics literature showing that monopoly power is affected by trading institutions. In this paper, we study whether trading institutions themselves can shape agents' market behavior through the formation of anchors. We recreate experimentally five different double-auction market structures (perfect competition, perfect competition with quotas, cartel on price, cartel on price with quotas, and monopoly) in a within-subject design, varying the order of markets implementation. We investigate whether monopoly power endures the formation of price anchors emerged in previously implemented market structures. Results from our classroom experiments suggest that double-auction trading institutions succeed in preventing monopolists from exploiting their market power. Furthermore, the formation of price anchors in previously implemented markets negatively impacts on monopolists' power in later market structures.

Measuring Knightian uncertaintyJournal articleAndreas Dibiasi et David Iselin, Empirical Economics, Volume 61, Issue 4, pp. 2113-2141, 2021

Knightian uncertainty represents a situation in which it is no longer possible to form expectations about future events. We propose a method to directly measure Knightian uncertainty. Our approach relies on firm-level data and measures the share of firms that do not formalize expectations about their future demand. We construct the Knightian Uncertainty Indicator for Switzerland and show that the indicator is able to identify times of high uncertainty. We evaluate the indicator by comparing it to established uncertainty measures. We find that a one standard deviation innovation of the Knightian Uncertainty Indicator leads to a negative and persistent reduction of investment.

Donneurs et acteurs de terrain : une étude quantitative de la délégation et de la fragmentation de l’aide humanitaireJournal articleNathalie Ferrière, Mondes en développement, Volume 195, Issue 3, pp. 109-128, 2021

La part de l’aide humanitaire croît dans l’aide totale. Or les acteurs impliqués restent peu étudiés. Cet article documente la fragmentation de l’aide à un double niveau : celui des donneurs et celui des acteurs de terrains. Le jeu de délégation entre les deux peut réduire les effets négatifs de la fragmentation de l’aide. À partir de trois études de cas, le lien entre fragmentation, délégation et efficacité de l’aide humanitaire est illustré et les coûts et bénéfices potentiels de la délégation et de la fragmentation discutés.