Publications

La plupart des informations présentées ci-dessous ont été récupérées via RePEc avec l'aimable autorisation de Christian Zimmermann
Better accounting for long-term health effects in economic assessments: an illustration for air pollution in the Canton of GenevaJournal articleO. Chanel et I. Cucchi, Public Health, Volume 233, pp. 31-37, 2024

Objectives
We propose a general framework for estimating long-term health and economic effects that takes into account four time-related aspects. We apply it to a reduction in exposure to air pollution in the Canton of Geneva.
Study design
Methodological developments on the evaluation of long-term economic and health benefits, with an empirical illustration.
Methods
We propose a unified framework—the comprehensive impact assessment (CIA)—to assess the long-term effects of morbidity and mortality in health and economic terms. This framework takes full account of four time-related issues: cessation lag, policy/technical implementation timeframe, discounting and time horizon. We compare its results with those obtained from standard quantitative health impact assessment (QHIA) in an empirical illustration involving air pollution reduction in the canton of Geneva.
Results
We find that by neglecting time issues, the QHIA estimates greater health and economic benefits than the CIA. The overestimation is about 50% under reasonable assumptions and increases ceteris paribus with the magnitude of the cessation lag and the discount factor. It decreases both with the time horizon and with the implementation timeframe.
Conclusion
A proper evaluation of long-term health and economic effects is an important issue when they are to be used in cost-benefit analyses, particularly for mortality, which often represents the largest fraction. We recommend using the CIA to calculate more accurate values.

Knowledge-based structural changeJournal articleKevin Genna, Christian Ghiglino, Kazuo Nishimura et Alain Venditti, Economic Theory, 2024

How will structural change unfold beyond the rise of services? Motivated by the observed dynamics within the service sector we propose a model of structural change in which productivity is endogenous and output is produced with two intermediate substitutable capital goods. In the productive sector the accumulation of specialized skills leads to an unbounded increase in TFP, as sector becoming asymptotically dominant. We are then able to recover the increasing shares of workers, the increasing real and nominal shares of the output observed in productive service and IT sectors in the US. Interestingly, the economy follows a growth path converging to a particular level of wealth that depends on the initial price of capital and knowledge. As a consequence, countries with the same fundamentals but lower initial wealth will be characterized by lower asymptotic wealth.

High inflation during Russia–Ukraine war and financial market interaction: Evidence from C-Vine Copula and SETAR modelsJournal articleTaher Hamza, Hayet Ben Haj Hamida, Mehdi Mili et Mina Sami, Research in International Business and Finance, Volume 70, pp. 102384, 2024

This paper examines the interaction between three financial markets: energy and non-energy commodities, bonds and equities, in a particular context of high inflation worldwide, that of Russia–Ukraine war. Our data cover the period January 2016-October 2022. Using a SETAR-GARCH C-Vine Copula model, we provide evidence of two inflation breakouts within COVID pandemic and shortly before Russia–Ukraine war, for all assets considered, and particularly for US 10-Year bond, as an inflation-indexed asset. Over the Russia–Ukraine war period, both linear and nonlinear models explain the studied assets’ behavior faced with high inflation. C-Vine Copula analysis shows that oil prices (WTI), as an inflation-producing assets, impact the volatility of financial markets (VIX) in times of war. This analysis indicates also that the NASDAQ index, as an inflation-exposed assets, is sensitive to commodities and energy prices that drive inflation. Furthermore, we find a high positive Kendall’s tau for all combinations between US 10-Year and all other assets. These results provide strong evidence of the association between US 10-Year futures, as a vehicle of inflation, and all studied assets. Lastly, our findings confirm the evidence that Russia–Ukraine war generated two significant shocks, Gas (NG) prices and financial markets’ volatility (VIX). This study is of crucial interest to policy and decision makers to the extent that it provides a framework for understanding, in a context of high inflation, the mechanisms linked to the vehicles for transmitting this inflation, its pricing process, and its impact on the equity market.

Consumer impatience: A key motive for Covid-19 vaccinationJournal articleMarlène Guillon, Phu Nguyen-Van, Bruno Ventelou et Marc Willinger, Journal of Behavioral and Experimental Economics, Volume 110, pp. 102190, 2024

We study the behavioral determinants of COVID-19 vaccination uptake. The vaccine-pass policy, implemented in several countries in 2021, conditioned the access to leisure and consumption places to being vaccinated against COVID-19 and created an unprecedented situation where individuals’ access to consumption goods and vaccine status were interrelated. We rely on a quasi-hyperbolic discounting model to study the plausible relationships between time preference and the decision to vaccinate in such context. We test the predictions of our model using data collected from a representative sample of the French population (N = 1034) in August and September 2021. Respondents were asked about their COVID-19 vaccination status (zero, one, or two doses), as well as their economic and social preferences. Preference elicitations were undertaken online through incentivized tasks, with parallel collection of self-stated preferences. Factors associated with COVID-19 vaccination were investigated using a logistic model. Both elicited and stated impatience were found to be positively associated with COVID-19 vaccination decisions. These results suggest that impatience is a key motivational lever for vaccine uptake in a context where the vaccination decision is multidimensional and impacts the consumption potential. Results also serve to highlight the potential effectiveness of public communications campaigns based on time preferences to increase vaccination coverage.

On the (de)stabilization role of protectionismJournal articleNastasia Henry et Alain Venditti, Journal of Mathematical Economics, pp. 102993, 2024

To what extent protectionism affects growth and (de)stabilizes the economies? Although the impact of protectionism on growth has been widely explored without reaching a consensus, few has been said on its impact on macroeconomic stability. The present paper attempts to gauge more precisely its implications using a Barro-type (Barro, 1990) endogenous growth model with public debt and credit constraint where tariffs are a proxy of protectionism. Our main result is to show that when the debt level is high, and the share of foreign goods in total consumption is large enough, increasing tariffs may have a destabilizing effect generating some expectation coordination failures between multiple equilibria. We also exhibit some trade-off between tariffs and growth as tariffs are beneficial only to the low growth equilibrium which may only appear when the international interest rate is low enough. Finally, focusing on the local stability property, we show that the high BGP is always characterized by local indeterminacy, while the low BGP is always a saddle point. We then prove that tariffs may be responsible for the existence of large self-fulfilling fluctuations.

A boosted DC algorithm for non-differentiable DC components with non-monotone line searchJournal articleOrizon Ferreira, Elianderson Santos et João Carlos Souza, Computational Optimization and Applications, Volume 88, Issue 3, pp. 783-818, 2024

We introduce a new approach to apply the boosted difference of convex functions algorithm (BDCA) for solving non-convex and non-differentiable problems involving difference of two convex functions (DC functions). Supposing the first DC component differentiable and the second one possibly non-differentiable, the main idea of BDCA is to use the point computed by the DC algorithm (DCA) to define a descent direction and perform a monotone line search to improve the decreasing the objetive function accelerating the convergence of the DCA. However, if the first DC component is non-differentiable, then the direction computed by BDCA can be an ascent direction and a monotone line search cannot be performed. Our approach uses a non-monotone line search in the BDCA (nmBDCA) to enable a possible growth in the objective function values controlled by a parameter. Under suitable assumptions, we show that any cluster point of the sequence generated by the nmBDCA is a critical point of the problem under consideration and provide some iteration-complexity bounds. Furthermore, if the first DC component is differentiable, we present different iteration-complexity bounds and prove the full convergence of the sequence under the Kurdyka-\L{}ojasiewicz property of the objective function. Some numerical experiments show that the nmBDCA outperforms the DCA such as its monotone version.

Companies should care about the health troubles of their employees. The results of a French survey on medically assisted reproduction (MAR)Journal articleBlandine Courbiere, Michel Dalmas et Arnaud Lacan, Journal of General Management, pp. 03063070241250091, 2024

Several factors can deeply affect employees’ quality of life at work. Work-life balance, subjective well-being and job satisfaction are three of these factors and it is in the best interest of companies to handle these topics carefully. This is a sine qua non condition of the strength and the quality of relationships with employees. It is also a source of confidence for employees, especially where this is being mediated through Human Resource (HR) processes. Our article studies the quality of life at work in the particular context of an MAR healthcare pathway that exacerbates the consequences for employees. Our work with hundreds of people enduring an MAR process shows that depending on whether firms take this situation into account or not, employees will feel either well-being or ill-being and will have different burnout or job satisfaction levels. All these variables influence their commitment and job performance. These links between a healthcare pathway and quality of life at work on the one hand, and between the quality of work and performance on the other hand, should lead employers to support employees in a personal vulnerable situation. The strength and the quality of the support provided by the HR function and the management is therefore a key point in the level of confidence that exists between firms and their employees.

Association between mindfulness and risk and time preferencesJournal articleSebastien Duchêne, Marlène Guillon et Ismael Rafai, Journal of the Economic Science Association, 2024

Many studies have investigated the role of socio-demographic factors (including gender, age, race), cognitive ability and cultural factors on time and risk preferences. Yet, research regarding the effect of mindfulness on risk and time preferences has been limited. This study investigates the association between mindfulness and time/risk preferences. We conducted a survey on a representative sample of the French adult population (N = 1154) in Spring 2020. We assessed individual mindfulness through the Mindful Attention Awareness Scale (MAAS), and measured time and risk preferences with incentive-compatible economic games as well as self-reported questionnaires. Our results suggest that a higher level of mindfulness is associated with higher risk aversion and patience for stated preferences, but we found no relationship for revealed ones. We also observe that a higher level of mindfulness is related to greater time consistency, as we found a negative and significant association between the MAAS and the present and future biases.

Abstract reasoning, theory of mind and character development in the schoolJournal articleSule Alan et Betul Turkum, Journal of Economic Behavior & Organization, Volume 221, pp. 307-326, 2024

We show that the development of abstract reasoning and cognitive empathy (theory of mind) is severely hindered when children are deprived of the stimulation of a school environment. We document significantly lower abstract reasoning and cognitive empathy scores in elementary school children who returned from an extended school closure caused by the Covid-19 pandemic relative to proximate pre-pandemic cohorts. This developmental delay has a significant socioeconomic gradient, with underprivileged children experiencing more substantial delays. We also document a significant disruption in the development of socioemotional skills: 0.24 sd lower grit, 0.43 sd lower emotional empathy, 0.06 sd lower epistemic curiosity, and 0.24 sd higher impulsivity. About eight months of school exposure results in a remarkable recovery in abstract reasoning and theory of mind for all socioeconomic groups. However, the measured levels still indicate significant delays relative to the expected developmental trajectories. No notable improvements are observed in socioemotional skills except for curiosity. These findings reveal that the damage school closures inflicted on children goes beyond well-documented academic losses and highlight the crucial role of the school environment in fostering fundamental cognition and socioemotional development in children.

Does pay inequality affect worker effort? An assessment of experimental designs and evidenceJournal articleMarco Fongoni, Journal of Economic Behavior & Organization, Volume 220, Issue C, pp. 697-716, 2024

This paper develops a theoretical framework to think about employees' effort choices, and applies this framework to assess the ability of existing experimental designs to identify the effect of pay inequality on worker effort. The analysis shows that failure to control for a number of confounds—such as reciprocity towards the employer in multi-lateral gift-exchange games (vertical fairness), or the incentive to increase effort when feeling underpaid under piece rates (income targeting)—may lead to inaccurate interpretation of evidence of treatment effects. In light of these findings, the paper provides a set of recommendations on how to improve identification in the design of controlled experiments in the future.