Publications
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.
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.
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.
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.
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.
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.
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.
Given that poor individuals face worse survival conditions than non-poor individuals, one can expect that a steeper income gradient in mortality leads, through stronger income-based selection, to a lower poverty rate at the old age (i.e. the "missing poor" hypothesis). This paper uses U.S. state-level data on poverty at age 65+ and life expectancy by income levels to provide an empirical test of the missing poor hypothesis. Using average temperature as an instrument for mortality differentials, we show that instrumented changes in mortality differentials have a negative and statistically significant effect on old-age poverty: a 1 % increase in the mortality differential implies a 16 % decrease in the 65+ headcount poverty rate. Using those regression results, we compute hypothetical old-age poverty rates while neutralizing the impact of the income gradient in mortality, and show that correcting for heterogeneity in income-based selection effects modifies the comparison of old-age poverty prevalence across states.
This paper develops an overlapping generations model that links a public health system to a pay-as-you-go (PAYG) pension system. It relies on two assumptions. First, the health system directly finances curative health spending on the elderly. Second, public pensions partially depend on health status by introducing a component indexed to society’s average level of old-age disability. Reducing the average disability rate in the economy then lowers pension benefits as the need to finance long-term care services also drops. We study the effects of introducing such a ‘comprehensive’ Social Security system on individual decisions, capital accumulation, and welfare. We first show that health investments can boost savings and capital accumulation under certain conditions. Second, if individuals are sufficiently concerned with their health when old, it is optimal to introduce a health-dependent pension system, as this will raise social welfare compared to a system where pensions are not tied to the society’s average level of old-age disability. Our analysis thus highlights an important policy recommendation: making PAYG pension schemes partially health-dependent can be beneficial to society.
A common thread in the literature shows that an oil price shock can have a major impact on global economic conditions. We examine the global dimensions of changes to the global oil price and world economic uncertainty using three model types: ordinary least square (OLS); general additive model (GAM); and non-linear vector autoregression (VAR) model with local projections (LP). Our study highlights a positive and statistically significant effect of oil prices on economic uncertainty during non-expansionary periods, yet the impact is negative on economic uncertainty during periods of economic growth. Using a VAR-LP we analyze the global dimensions of a world oil price shock on global economic conditions and investigate whether there is consistency in how an oil price shock influences economic growth, consumer prices and economic uncertainty based on the state of economic conditions. The empirical evidence shows that during an expansionary (a non-expansionary) period, the impact of an oil price shock lowers (elevates) economic uncertainty. The empirical evidence from the three model types taken together indicate a presence of state dependence on the influence of an oil price shock.
