Publications

La plupart des informations présentées ci-dessous ont été récupérées via RePEc avec l'aimable autorisation de Christian Zimmermann
Bank liquidity creation: A new global dataset for developing and emerging countriesJournal articleCarmela D’Avino, Eric Girardin et Mimoza Shabani, Review of World Economics, Volume 158, pp. 529-570, 2022

The pre-Global Financial Crisis build-up, followed by the post-crisis collapse, in bank liquidity creation in developed countries is well-documented (Berger and Bowman, Berger and Bouwman, Review of Financial Studies 22:3779–3837, 2009). Comparable analyses on developing and emerging countries (DECs) have been severely hindered by the lack of detailed bank-by-bank balance sheet data. This paper proposes a new, high-frequency, Aggregate Bank Liquidity Creation (A-BLC) measure for 114 DECs on a comparable cross-country basis, which relies on macroeconomic, country-wide, banking systems’ balance sheet data. The A-BLC database allows us to assess the extent of bank fragility arising from illiquidity associated with intermediation at the banking system level for every DEC, at a monthly frequency over the period 2001–2016. Our measure captures more accurately than other measures proposed in the literature the evolution of bank liquidity creation in the DECs. Stylised facts and panel-regression analysis suggest a sharp pre-crisis build-up and post-crisis fall in liquidity creation in DECs, larger then that observed for developed countries. In addition, financial depth and stability appear as particularly important drivers of A-BLC in DECs.

Hepatitis B in Senegal: A Successful Infant Vaccination Program but Urgent Need to Scale Up Screening and Treatment (ANRS 12356 AmBASS survey)Journal articleLauren Perieres, Aldiouma Diallo, Fabienne Marcellin, Marie Libérée Nishimwe, El Hadji Ba, Marion Coste, Gora Lo, Philippe Halfon, Coumba Toure Kane, Gwenaelle Maradan, et al., Hepatology Communications, Volume 6, Issue 5, pp. 1005-1015, 2022

Senegal introduced the infant hepatitis B virus (HBV) vaccination in 2004 and recently committed to eliminating hepatitis B by 2030. Updated epidemiological data are needed to provide information on the progress being made and to develop new interventions. We estimated the prevalence of hepatitis B surface antigen (HBsAg) in children and adults living in rural Senegal and assessed hepatitis B treatment eligibility. A cross-sectional population-based serosurvey of HBsAg was conducted in 2018-2019 in a large sample (n = 3,118) of residents living in the Niakhar area (Fatick region, Senegal). Individuals positive for HBsAg subsequently underwent clinical and biological assessments. Data were weighted for age and sex and calibrated to be representative of the area's population. Among the 3,118 participants, 206 were HBsAg positive (prevalence, 6.9%; 95% confidence interval [CI], 5.6-8.1). Prevalence varied markedly according to age group in individuals aged 0-4, 5-14, 15-34, and >= 35 years as follows: 0.0% (95% CI, 0.00-0.01); 1.5% (95% CI, 0.0-2.3); 12.4% (95% CI, 9.1-15.6); and 8.8% (95% CI, 6.1-11.5), respectively. Of those subsequently assessed, 50.9% (95% CI, 41.8-60.0) had active HBV infection; 4 (2.9%; 95% CI, 0.9-9.4) were eligible for hepatitis B treatment. Conclusion: In this first population-based serosurvey targeting children and adults in rural Senegal, HBsAg prevalence was very low in the former, meeting the World Health Organization's (WHO) < 1% HBsAg 2020 target; however, it was high in young adults (15-34 years old) born before the HBV vaccine was introduced in 2004. To reach national and WHO hepatitis elimination goals, general population testing (particularly for adolescents and young adults), care, and treatment scale-up need to be implemented.

Nudging for lockdown: behavioural insights from an online experimentJournal articleThierry Blayac, Dimitri Dubois, Sebastien Duchêne, Phu Nguyen-Van, Ismael Rafai, Bruno Ventelou et Marc Willinger, Social Psychology, Volume 53, Issue 3, pp. 133-151, 2022

We test the effectiveness of a social comparison nudge (SCN) to enhance lockdown compliance during the COVID-19 pandemic using a French representative sample (N = 1,154). Respondents were randomly assigned to a favorable/unfavorable informational feedback (daily road traffic mobility patterns, in Normandy - a region of France) on peer lockdown compliance. Our dependent variable was the intention to comply with a possible future lockdown. We controlled for risk, time, and social preferences and tested the effectiveness of the nudge. We found no evidence of the effectiveness of the SCN among the whole French population, but the nudge was effective when its recipient and the reference population shared the same geographical location (Normandy). Exploratory results on this subsample (N = 52) suggest that this effectiveness could be driven by noncooperative individuals.

The Macroeconomic Impact of the 1918–19 Influenza Pandemic in SwedenJournal articleMartin Karlsson, Mykhailo Matvieiev et Maksym Obrizan, The B.E. Journal of Macroeconomics, 2022

In this paper, we develop an overlapping generations model with endogenous fertility and calibrate it to the Swedish historical data in order to estimate the economic cost of the 1918–19 influenza pandemic. The model identifies survivors from younger cohorts as main benefactors of the windfall bequests following the influenza mortality shock. We also show that the general equilibrium effects of the pandemic reveal themselves over the wage channel rather than the interest rate, fertility or labor supply channels. Finally, we demonstrate that the influenza mortality shock becomes persistent, driving the aggregate variables to lower steady states which costs the economy 1.819% of the output loss over the next century.

Quand les bailleurs de fonds doivent se positionner face aux États-Unis : le cas de l’aide au planning familialJournal articleNathalie Ferrière, Revue d'économie du développement, Volume 31, Issue 2-3, pp. 71-77, 2022

L’aide internationale au planning familial est dominée par un bailleur de fonds, les États-Unis, dont l’allocation dépend de débats nationaux autour de l’avortement. Cet article examine comment les autres donateurs ajustent leur financement en réaction.Codes JEL : C26, F35, I15, I18, J13, O15.

Le populiste et le rapport aux chiffresBook chapterAlain Trannoy, In: Des économistes répondent aux populistes, Hippolyte d'Albis et Françoise Benhamou (Eds.), 2022-04, pp. 49-58, Éditions Odile Jacob, 2022

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An evolutionary finance model with short selling and endogenous asset supplyJournal articleRabah Amir, Sergei Belkov, Igor V. Evstigneev et Thorsten Hens, Economic Theory, Volume 73, Issue 2, pp. 655-677, 2022

Evolutionary finance focuses on questions of “survival and extinction” of investment strategies (portfolio rules) in the market selection process. It analyzes stochastic dynamics of financial markets in which asset prices are determined endogenously by a short-run equilibrium between supply and demand. Equilibrium is formed in each time period in the course of interaction of portfolio rules of competing market participants. A comprehensive theory of evolutionary dynamics of this kind has been developed for models in which short selling is not allowed and asset supply is exogenous. The present paper extends the theory to a class of models with short selling and endogenous asset supply.

The path towards herd immunity: Predicting COVID-19 vaccination uptake through results from a stated choice study across six continentsJournal articleStephane Hess, Emily Lancsar, Petr Mariel, Jürgen Meyerhoff, Fangqing Song, Eline van den Broek-Altenburg, Olufunke A. Alaba, Gloria Amaris, Julián Arellana, Leonardo J. Basso, et al., Social Science & Medicine, Volume 298, pp. 114800, 2022

Despite unprecedented progress in developing COVID-19 vaccines, global vaccination levels needed to reach herd immunity remain a distant target, while new variants keep emerging. Obtaining near universal vaccine uptake relies on understanding and addressing vaccine resistance. Simple questions about vaccine acceptance however ignore that the vaccines being offered vary across countries and even population subgroups, and differ in terms of efficacy and side effects. By using advanced discrete choice models estimated on stated choice data collected in 18 countries/territories across six continents, we show a substantial influence of vaccine characteristics. Uptake increases if more efficacious vaccines (95% vs 60%) are offered (mean across study areas = 3.9%, range of 0.6%–8.1%) or if vaccines offer at least 12 months of protection (mean across study areas = 2.4%, range of 0.2%–5.8%), while an increase in severe side effects (from 0.001% to 0.01%) leads to reduced uptake (mean = −1.3%, range of −0.2% to −3.9%). Additionally, a large share of individuals (mean = 55.2%, range of 28%–75.8%) would delay vaccination by 3 months to obtain a more efficacious (95% vs 60%) vaccine, where this increases further if the low efficacy vaccine has a higher risk (0.01% instead of 0.001%) of severe side effects (mean = 65.9%, range of 41.4%–86.5%). Our work highlights that careful consideration of which vaccines to offer can be beneficial. In support of this, we provide an interactive tool to predict uptake in a country as a function of the vaccines being deployed, and also depending on the levels of infectiousness and severity of circulating variants of COVID-19.

Applying the health capability profile to empirically study chronic hepatitis B in rural Senegal: a social justice mixed-methods study protocolJournal articleMarion Coste, Mouhamed Ahmed Badji, Aldiouma Diallo, Marion Mora, Sylvie Boyer et Jennifer J. Prah, BMJ Open, Volume 12, Issue 4, pp. e055957, 2022

Introduction:
Despite the early implementation of hepatitis B vaccination and the ongoing decentralisation of chronic hepatitis B (CHB) care, over 10% of the Senegalese adult population lives with CHB and liver cancer remains a main cause of death. Investigating factors associated with CHB infection, prevention of CHB-related morbidity, and prevention and treatment of mortality secondary to CHB calls for a holistic and multidimensional approach. This paper presents the adaptation of the health capability profile (HCP) to a specific epidemiological issue and empirical setting: it seeks to identify and analyse inter-related abilities and conditions (health capabilities) in relation to the CHB epidemic in the rural area of Niakhar, Senegal.
Methods and analysis:
This ongoing study relies on a sequential social justice mixed-methods design. The HCP is comprehensively adapted to CHB in rural Senegal and guides the design and conduct of the study. Objective and subjective data are collected at the individual level following a mixed-methods explanatory core design. The quantitative module, embedded in the ANRS12356 AmBASS cross-sectional survey (exhaustive sampling), is used to select a purposeful sampling of participants invited for one-on-one qualitative interviews. Additional data are collected at the institutional and community level through health facility surveys and an ethnography (in-depth interviews) of local and national CHB stakeholders. Data analysis adopts a synergistic approach to produce a multilayered analysis of individual HCPs and crosscutting analysis of the 15 health capabilities. The data integration strategy relies on a mixed-methods convergent core design, and will use 0–100 health capability scores as well as flow diagrams to measure and characterise levels of development and interactions among health capabilities, respectively.
Ethics and dissemination:
This study was approved by Senegalese and French authorities. Results dissemination through local workshops and scientific publications aim at fuelling effective policy change towards CHB-related health capability.

Set-valued variational principles. When migration improves quality of lifeJournal articleMajid Fakhar, Mohammadreza Khodakhah, Antoine Soubeyran et Jafar Zafarani, Journal of Applied and Numerical Optimization, Volume 4, Issue 1, pp. 37-51, 2022

In this paper, in the context of quasi-metric spaces, we obtain two set-valued versions of the Ekeland variational-type principle by means of lower and upper set less relations, for the case where the perturbations need not satisfy the triangle inequality. An application in terms of migration problems and quality of life is given.