Publications

La plupart des informations présentées ci-dessous ont été récupérées via RePEc avec l'aimable autorisation de Christian Zimmermann
Shutdown policies and worldwide conflictJournal articleNicolas Berman, Mathieu Couttenier, Nathalie Monnet et Rohit Ticku, Covid Economics, Volume 16, pp. 61-75, 2020

We provide real-time evidence on the impact of Covid-19 restrictions policies on conflicts globally. We combine daily information on conflict events and government policy responses to limit the spread of coronavirus to study how conflict levels vary following shutdown and lockdown policies. We use the staggered implementation of restriction policies across countries to identify their effect on conflict incidence and intensity. Our results show that imposing a nationwide shutdown reduces the likelihood of daily conflict by around 9 percentage points. The reduction is driven by a drop in the incidence of battles, protests and violence against civilians. Across actors the decline is significant for conflicts involving political militias, protesters and civilians. We also observe a significant cross-country heterogeneity in the effect of restriction policies on conflict: no conflict reduction is observed in low income countries and in societies more fractionalized along ethnic or religious lines. We discuss the potential channels that can explain this heterogeneity.

Sub-national allocation of COVID-19 tests: An efficiency criterion with an application to Italian regionsJournal articleChristelle Baunez, Mickael Degoulet, Stéphane Luchini, Patrick A. Pintus et Miriam Teschl, Covid Economics, Volume 12, pp. 192-209, 2020

Tests are crucial to know about the number of people who have fallen ill with COVID-19 and to understand in real-time whether the dynamics of the pandemic is accelerating or decelerating. But tests are a scarce resource in many countries. The key but still open question is thus how to allocate tests across sub-national levels. We provide a data-driven and operational criterion to allocate tests efficiently across regions or provinces, with the view to maximize detection of people who have been infected. We apply our criterion to Italian regions and compute the shares of tests that should go to each region, which are shown to differ significantly from the actual distribution.Mickael Degoule

The post-crises output growth effects in a globalized economyJournal articleBertrand Candelon, Alina Carare, Jean-Baptiste Hasse et Jing Lu, International Economics, Volume 161, pp. 139-158, 2020

This paper investigates the persistent impact of financial crises on economic growth in different regimes of globalization. Relying on a nonlinear dynamic panel representation, this paper explains why the effects of globalization on growth weave into a tale of two opposite narratives. On average, a country experiences higher growth, the more open and integrated it is into the world. However, countries can also experience persistently lower medium-term output growth after a financial crisis, once globalization reaches a certain threshold. The benefits, as well as vulnerabilities, accrue earlier in the globalization process for low-income countries.

Weather shocksJournal articleEwen Gallic et Gauthier Vermandel, European Economic Review, Volume 124, pp. 103409, 2020

How much do weather shocks matter? The literature addresses this question in two isolated ways: either by looking at long-term effects through the prism of calibrated theoretical models, or by focusing on both short and long terms through the lens of empirical models. We propose a framework that reconciles these two approaches by taking the theory to the data in two complementary ways. We first document the propagation mechanism of a weather shock using a Vector Auto-Regressive model on New Zealand Data. To explain the mechanism, we build and estimate a general equilibrium model with a weather-dependent agricultural sector to investigate the weather’s business cycle implications. We find that weather shocks: (i) explain about 35% of GDP and agricultural output fluctuations in New Zealand; (ii) entail a welfare cost of 0.30% of permanent consumption; (iii) critically increases the macroeconomic volatility under climate change, resulting in a higher welfare cost peaking to 0.46% in the worst case scenario of climate change.

Who’ll stop lying under oath? Empirical evidence from tax evasion gamesJournal articleNicolas Jacquemet, Stéphane Luchini, Antoine Malézieux et Jason F. Shogren, European Economic Review, Volume 124, pp. 103369, 2020

Using two earned income/tax declaration experimental designs we show that only partial liars are affected by a truth-telling oath, a non-price commitment device. Under oath, we see no change in the number of chronic liars and fewer partial liars. Rather than smoothly increasing their compliance, we also observe that partial liars who respond to the oath, respond by becoming fully honest under oath. Based on both response times data and the consistency of subjects when several compliance decisions are made in a row, we show that partial lying arises as the result of weak preferences towards profitable honesty. The oath only transforms people with weak preferences for lying into being committed to the truth.

Quality and price personalization under customer recognition: A dynamic monopoly model with contrasting equilibriaJournal articleDidier Laussel, Ngo Van Long et Joana Resende, Journal of Economic Dynamics & Control, Volume 114, pp. 103869, 2020

We present a model of market hyper-segmentation, where a monopolist acquires within a short time all information about the preferences of consumers who purchase its vertically differentiated products. The firm offers a new price/quality schedule after each commitment period. Lower consumer types may have an incentive to delay their purchases until next period to obtain a better introductory offer. The monopolist counters this incentive by offering higher informational rents. Considering the dynamic game played by the monopolist and its customers, we find that there is always a Markov perfect equilibrium (MPE) in which the firm immediately sells the good to all customers, offering the Mussa-Rosen static equilibrium schedule to first time customers (and getting full commitment profits). However, if the commitment period between two offers is long enough, there is another MPE with gradual market expansion. Contrary to the Coasian result for a durable-good monopoly, we find that in both equilibria the profit of the monopolist increases (and the aggregate consumers surplus decreases) as the interval of commitment shrinks. The model yields policy implications for regulations on collection and storage of customers information. (C) 2020 Elsevier B.V. All rights reserved.

Ma vie auprès de Bertrand Lemennicier, par Thalia le chat.Journal articleAntoine Gentier, Journal des libertés, Issue 8, pp. 101-110, 2020

Avant-propos
L’éloge funèbre est un exercice dont la solennité peut nuire à la mémoire de celui qui le reçoit. Dans le cas de Bertrand Lemennicier, une partie intangible de sa personnalité, cette capacité à partir d’un exemple loufoque pour développer un argument sérieux, de faire joyeusement des discussions complexes, et cette attitude de distance souriante face aux diverses formes de l’argumentation sont difficilement atteignables par un éloge standard. Avec le soutien de Marie Madeleine son épouse, de ses deux filles Alexandra et Béatrice, et de la théorie économique, j’ai pensé qu’un éloge félin serait plus adapté. Le Journal des Libertés a donc mis tout en œuvre pour recueillir le témoignage de Thalia, le chat qui a passé 17 ans chez les Lemennicier.

How will the main risk factors contribute to the burden of non-communicable diseases under different scenarios by 2050? A modelling studyJournal articleMarion Devaux, Alienor Lerouge, Giovanna Giuffre, Susanne Giesecke, Sara Baiocco, Andrea Ricci, Francisco Reyes, David Cantarero, Bruno Ventelou et Michele Cecchini, PLoS ONE, Volume 15, Issue 4, pp. e0231725, 2020

Background:
The future burden of non-communicable diseases (NCDs) depends on numerous factors such as population ageing, evolution of societal trends, behavioural and physiological risk factors of individuals (e.g. smoking, alcohol use, obesity, physical inactivity, and hypertension). This study aims to assess the burden of NCDs in Europe by 2050 under alternative scenarios.

Methods:
This study combines qualitative and quantitative forecasting techniques to examine how population health in Europe may evolve from 2015 to 2050, taking into account future societal trends. Four scenarios were developed (one business-as-usual scenario, two response scenarios and one pessimistic scenario) and assessed against 'best' and 'worst'-case scenarios. This study provides quantitative estimates of both diseases and mortality outcomes, using a microsimulation model incorporating international survey data.

Findings:
Each scenario is associated with a different risk factor prevalence rate across Europe during the period 2015-2050. The prevalence and incidence of NCDs consistently increase during the analysed time period, mainly driven by population ageing. In more optimistic scenarios, diseases will appear in later ages, while in the pessimistic scenarios, NCDs will impair working-age people. Life expectancy is expected to grow in all scenarios, but with differences by up to 4 years across scenarios and population groups. Premature mortality from NCDs will be reduced in more optimistic scenarios but stagnate in the worst-case scenario.

Interpretation:
Population ageing will have a greater impact on the spread of NCDs by 2050 compared to risk factors. Nevertheless, risk factors, which are influenced by living environments, are an important factor for determining future life expectancy in Europe.

Inconsistency transmission and variance reduction in two-stage quantile regressionJournal articleTae-Hwan Kim et Christophe Muller, Communications in Statistics - Simulation and Computation, Volume 49, Issue 4, pp. 1044-1077, 2020

In this paper, we propose a new variance reduction method for quantile regressions with endogeneity problems, for alpha-mixing or m-dependent covariates and error terms. First, we derive the asymptotic distribution of two-stage quantile estimators based on the fitted-value approach under very general conditions. Second, we exhibit an inconsistency transmission property derived from the asymptotic representation of our estimator. Third, using a reformulation of the dependent variable, we improve the efficiency of the two-stage quantile estimators by exploiting a tradeoff between an inconsistency confined to the intercept estimator and a reduction of the variance of the slope estimator. Monte Carlo simulation results show the fine performance of our approach. In particular, by combining quantile regressions with first-stage trimmed least-squares estimators, we obtain more accurate slope estimates than 2SLS, 2SLAD and other estimators for a broad set of distributions. Finally, we apply our method to food demand equations in Egypt.

Lie of the weak: Inconsistent corporate social responsibility activities of Chinese zombie firmsJournal articleShaozhen Han, Guoming Li, Michel Lubrano et Zhou Xun, Journal of Cleaner Production, Volume 253, pp. 119858, 2020

This study investigates the differences between zombie firms and non-zombie firms in corporate social responsibility activities such as reporting, disclosure and fulfillment. Using Chinese listing company data collected from 2009 to 2016, we apply a three stage model with a double Heckman correction to deal with potential self-selection/endogeneity bias and to measure the differences consistently. We found that zombie firms are less willing to release standalone corporate social responsibility reports than non-zombie firms. Among companies that release standalone corporate social responsibility reports, the corporate social responsibility disclosure of zombie firms is at least not worse than non-zombie firms, but the corporate social responsibility fulfillment is significantly lower. We conclude from this gap between disclosure and fulfillment to the hypocritical behavior of zombie firms, due to the absence of control in corporate social responsibility. We suggest that government should enhance supervision over zombie firms’ corporate social responsibility activities and subsidies towards them in order to lower their economic damage. Supplementary analyses provide some clues concerning the heterogeneity of inconsistence in term of external support characteristics, ownership and censorship which require further studies.