Publications

La plupart des informations présentées ci-dessous ont été récupérées via RePEc avec l'aimable autorisation de Christian Zimmermann
The Bayesian approach to poverty measurementBook chapterMichel Lubrano et Zhou Xun, In: Research Handbook on Measuring Poverty and Deprivation, J. Silber (Eds.), 2023-03, Volume 8, pp. 475-487, Edward Elgar Publishing, 2023

This chapter reviews the recent Bayesian literature on poverty measurement together with some new results. Using Bayesian model criticism, we revise the international poverty line. Using mixtures of lognormals to model income, we derive the posterior distribution for the FGT, Watts and Sen poverty indices, for TIP curves (with an illustration on child poverty in Germany) and for Growth Incidence Curves. The relation of restricted stochastic dominance with TIP and GIC dominance is detailed with an example based on UK data. Using panel data, we decompose poverty into total, chronic and transient poverty, comparing child and adult poverty in East Germany when redistribution is introduced. When panel data are not available, a Gibbs sampler can be used to build a pseudo panel. We illustrate poverty dynamics by examining the consequences of the Wall on poverty entry and poverty persistence in occupied West Bank.

New Challenges for Macroeconomic Policies: Economic Growth, Sustainable Development, Fiscal and Monetary PoliciesBookGilles Dufrénot, 2023-03, XXIV,451 pages, Springer International Publishing, 2023

This book examines the economic policies that will underpin the evolution of growth in industrialised economies in coming decades. The change in focus of policymakers away from short-term regulation and policies towards problems of structural change is discussed in relation to the Taylor rule and Fisher relationship. Both empirical observations and quantitative analyses are utilised to explore diverse but interrelating topics, including interest rates dynamics, macroeconomic equilibrium, economic vulnerability, poverty and inequality, environmental sustainability, and monetary and fiscal policies.
This book aims to propose policies that can produce economic growth without compromising social stability and environmental balances. It will be of interest to researchers and policymakers working within economic development and policy.

Pollution in a globalized world: Are debt transfers among countries a solution?Journal articleMarion Davin, Mouez Fodha et Thomas Seegmuller, International Journal of Economic Theory, Volume 19, Issue 1, pp. 21-38, 2023

We analyze the effects of a debt relief, that is, a decrease in public debt of a low-income country financed by a high-income country, on environmental quality. Under perfect mobility of assets, the debt relief increases the overall capital stock, and environmental quality when public abatements are sufficiently efficient. Welfare in both countries can also improve. Under a weak mobility of assets, capital does no more increase in the richest country, but environmental quality can improve. This comes from a crowding-out effect of debt in the high-income country, which does no more take place when the mobility of assets is significant.

Inflation and the Income Share of the Rich: Evidence for 14 OECD CountriesJournal articleMehdi El Herradi, Jakob de Haan et Aurelien Leroy, Review of Income and Wealth, Volume 69, Issue 1, pp. 170-194, 2023

This paper examines the distributional implications of inflation on top income shares in 14 advanced economies using data over the period 1920–2016. We use local projections to analyze how top income shares respond to an inflation shock, and panel regressions in which all variables are defined as 5-year averages to examine the impact of inflation on the position of the top-one-percent in the long run. Our findings suggest that inflation reduces the share of national income held by the top 1 percent. Furthermore, we find that inflation shocks and long-run inflation have similar effects on top income shares.

A novel community-based therapeutic education program for reducing alcohol-related harms and stigma in people with alcohol use disorders: A quasi-experimental study (ETHER study)Journal articleTangui Barré, Clémence Ramier, Saskia Antwerpes, Marie Costa, Morgane Bureau, Gwenaelle Maradan, Vincent Di Beo, Christophe Cutarella, Jacques Leloutre, Olivier Riccobono-Soulier, et al., Drug and Alcohol Review, Volume 42, Issue 3, pp. 664-679, 2023

Introduction Alcohol use disorder (AUD) is associated with a significant disease burden in France, where alcohol use is deeply rooted in culture. However, the treatment gap is large because of several barriers, including stigmatisation and drinkers' apprehension about total abstinence. However, standardised and evidence-based interventions based on controlled-drinking for people with AUD are lacking. We aimed to assess the effectiveness of a novel community-based French therapeutic patient education (TPE) program for people with AUD named Choizitaconso. Methods A before-after non-randomised quasi-experimental study, named ETHER, was designed and implemented with people living with AUD, over a period of 6 months. The primary outcome was percentage change in the number of alcohol-related harms experienced. Secondary outcomes were percentage changes in psycho-social patient-reported and community-validated outcomes. Participants in the intervention group (n = 34) benefited from the 10-week TPE program Choizitaconso, while the comparison group (n = 58) received standard care. The Kruskall–Wallis and chi-squared or Fisher's exact tests were used to compare before-after changes in variables in both groups. Linear regression models were used to test for the effect of study group on each outcome and to test for the effect of alcohol consumption as a confounder. Results At 6 months, all outcomes but one either remained stable or numerically improved in both groups. Internalised stigma significantly improved in the intervention group (p = 0.026) but not in the comparison group (p = 0.207), with a significant group effect (p = 0.014). Discussion and Conclusions This study demonstrates the effectiveness of the Choizitaconso TPE program on community-validated outcomes, especially internalised stigma.

Predicting health services utilization using a score of perceived barriers to medical care: evidence from rural SenegalJournal articleMarion Coste et Mârwan-al-Qays Bousmah, BMC Health Services Research, Volume 23, Issue 1, pp. 263, 2023

Background
Ensuring access to healthcare services is a key element to achieving the Sustainable Development Goal 3 of "promoting healthy lives and well-being for all" through Universal Health Coverage (UHC). However, in the context of low- and middle-income countries, most studies focused on financial protection measured through catastrophic health expenditures (CHE), or on health services utilization among specific populations exhibiting health needs (such as pregnancy or recent sickness).
Methods
This study aims at building an individual score of perceived barriers to medical care (PBMC) in order to predict primary care utilization (or non-utilization). We estimate the score on six items: (1) knowing where to go, (2) getting permission, (3) having money, (4) distance to the facility, (5) finding transport, and (6) not wanting to go alone, using individual data from 1787 adult participants living in rural Senegal. We build the score via a stepwise descendent explanatory factor analysis (EFA), and assess its internal consistency. Finally, we assess the construct validity of the factor-based score by testing its association (univariate regressions) with a wide range of variables on determinants of healthcare-seeking, and evaluate its predictive validity for primary care utilization.
Results
EFA yields a one-dimensional score combining four items with a 0.7 Cronbach's alpha indicating good internal consistency. The score is strongly associated-p-values significant at the 5% level-with determinants of healthcare-seeking (including, but not limited to, sex, education, marital status, poverty, and distance to the health facility). Additionally, the score can predict non-utilization of primary care at the household level, utilization and non-utilization of primary care following an individual's episode of illness, and utilization of primary care during pregnancy and birth. These results are robust to the use of a different dataset.
Conclusion
As a valid, sensitive, and easily documented individual-level indicator, the PBMC score can be a complement to regional or national level health services coverage to measure health services access and predict utilization. At the individual or household level, the PBMC score can also be combined with conventional metrics of financial risk protection such as CHE to comprehensively document deficits in, and progress towards UHC.

Web-scraping housing prices in real-time: The Covid-19 crisis in the UKJournal articleJean-Charles Bricongne, Baptiste Meunier et Sylvain Pouget, Journal of Housing Economics, Volume 59, pp. 101906, 2023

While official statistics provide lagged and aggregate information on the housing market, extensive information is available publicly on real-estate websites. By web-scraping them for the UK on a daily basis, this paper extracts a large database from which we build timely and highly granular indicators. One originality of the dataset is to focus on the supply side of the housing market, allowing to compute innovative indicators reflecting the sellers' perspective such as the number of new listings posted or how prices fluctuate over time for existing listings. Matching listing prices in our dataset with transacted prices from the notarial database, using machine learning, also measures the negotiation margin of buyers. During the Covid-19 crisis, these indicators demonstrate the freezing of the market and the “wait-and-see” behaviour of sellers. They also show that listing prices after the lockdown experienced a continued decline in London but increased in other regions.

Correcting the reproduction number for time-varying tests: A proposal and an application to COVID-19 in FranceJournal articleChristelle Baunez, Mickael Degoulet, Stéphane Luchini, Matteo L. Pintus, Patrick A. Pintus et Miriam Teschl, PLOS ONE, Volume 18, Issue 2, pp. e0281943, 2023

We provide a novel way to correct the effective reproduction number for the time-varying amount of tests, using the acceleration index (Baunez et al., 2021) as a simple measure of viral spread dynamics. Not correcting results in the reproduction number being a biased estimate of viral acceleration and we provide a formal decomposition of the resulting bias, involving the useful notions of test and infectivity intensities. When applied to French data for the COVID-19 pandemic (May 13, 2020—October 26, 2022), our decomposition shows that the reproduction number, when considered alone, characteristically underestimates the resurgence of the pandemic, compared to the acceleration index which accounts for the time-varying volume of tests. Because the acceleration index aggregates all relevant information and captures in real time the sizable time variation featured by viral circulation, it is a more parsimonious indicator to track the dynamics of an infectious disease outbreak in real time, compared to the equivalent alternative which would combine the reproduction number with the test and infectivity intensities.

Coercivity and generalized proximal algorithms: application—traveling around the worldJournal articleErik A. Papa Quiroz, Antoine Soubeyran et Paulo R. Oliveira, Annals of Operations Research, Volume 321, Issue 1, pp. 451-467, 2023

We present an inexact proximal point algorithm using quasi distances to solve a minimization problem in the Euclidean space. This algorithm is motivated by the proximal methods introduced by Attouch et al., section 4, (Math Program Ser A, 137: 91–129, 2013) and Solodov and Svaiter (Set Valued Anal 7:323–345, 1999). In contrast, in this paper we consider quasi distances, arbitrary (non necessary smooth) objective functions, scalar errors in each objective regularized approximation and vectorial errors on the residual of the regularized critical point, that is, we have an error on the optimality condition of the proximal subproblem at the new point. We obtain, under a coercivity assumption of the objective function, that all accumulation points of the sequence generated by the algorithm are critical points (minimizer points in the convex case) of the minimization problem. As an application we consider a human location problem: How to travel around the world and prepare the trip of a lifetime.

The role of investor behavior in emerging stock markets: Evidence from VietnamJournal articleThi Nha Truc Phan, Philippe Bertrand, Hong Hai Phan et Xuan Vinh Vo, The Quarterly Review of Economics and Finance, Volume 87, pp. 367-376, 2023

Exloring the role of different types of investors on stock market is crticial since different types of investors react and behave differently when making investment decision. The role of investor behavior is a very important issue in an immature stock market like Vietnam stock market because the market is characterized by a large number of individual investors and low reporting standard. Institutional and foreign investors however play an influential role due to their large exposure and strong investment expertise. Clearly, examining the role of investor behavior and its impact on the stock market in Vietnam is an important topic in finance. A significant body of empirical research has shown that investor behavior is an essential factor to explain stock price that the classical financial theory cannot explain. This research examines the role of investor behavior in stock market by examining the relationship between investor behavior and stock return using the Vietnamese stock exchange data. We create a sentiment index using the principal components analysis (PCA). Consistent with the sentiment and stock return literature, the research shows a negative contemporaneous relationship between investor sentiment and market return.