The limits of behavioral nudges to increase youth turnout: Experimental evidence from two French elections

International audienceThere is a significant gap in turnout between young people and older voters. The failure to instill a voting habit at an early age may have long term consequences in terms of future political participation as well as on other civic behaviors. Using a pre-registered online experiment with 3790 subjects, we implemented behavioral interventions aiming to stimulate youth turnout in the 2022 French presidential election. We rely on an innovative incentive scheme to measure their consequences on (self-reported) actual voting behavior. We also provide evidence on the effect of one behavioral intervention on youth turnout in a less salient election, the French legislative election that took place two months after the Presidential one. The results from the two experiments show the absence of any differences in turnout between the baseline and the treatment conditions. We investigate several mechanisms that can explain our results

A Lagrangian perspective reveals the carbon and oxygen budget of an oceanic eddy

International audienc

The Old Folks at Home: Parental Retirement and Adult Children'sWell-being

We here use UK data and exploit the State Pension eligibility age to establish the causal effect of parental retirement on adult children's well-being in a Fuzzy Regression Discontinuity Design analysis. Maternal retirement increases adult children's life and income satisfaction by 0.20 standard deviations in the short run. These impacts are stronger for adult children with lower incomes, with young children of their own, and who live close to their retired parents. We emphasise the critical role of intergenerational time transfers from retired mothers in enhancing their adult children's well-being

GI 725A b: A potential super-Earth detected with SOPHIE and SPIRou in an M dwarf binary system at 3.5 pc

International audienceWe report the discovery of a super-Earth candidate orbiting the nearby mid-M dwarf Gl 725A using the radial velocity (RV) method. The planetary signal has been independently identified using high-precision RVs from the SOPHIE and SPIRou spectrographs, in the optical and near-infrared (NIR) domains, respectively. We modelled the stellar activity signal jointly with the planet using two Gaussian processes, one for each instrument to account for the chromaticity of the stellar activity and instrumental systematics, along with a Keplerian model. The signal was significantly detected with a RV semi-amplitude of 1.67 ± 0.20 m/s. The planet Gl725A b is found to be in an orbit compatible with circular with a period of 11.2201 ± 0.0051 days. We analysed 27 sectors of TESS photometry, for which no transit event was found. We determined a minimum mass of Mp sin i = 2.78 ± 0.35 M⊕, which places the planet in the super-Earth regime. Using mass-radius relationships, we predict the planetary radius to be between 1.2 and 2.0 R⊕. The proximity of Gl 725A (at only 3.5 pc) makes this new exoplanet one of the closest to Earth and joins the group of S-type low-mass planets in short orbits (P < 15 days) around close M dwarfs

Dynamic assignment without money: Optimality of spot mechanisms

International audienceWe study a large market model of dynamic matching with no monetary transfers and a continuum of agents who have to be assigned items at each date. When the social planner can only elicit ordinal agents' preferences, we prove that under a mild regularity assumption, incentive compatible and ordinally efficient allocation rules coincide with spot mechanisms. The latter specify “virtual prices” for items at each date and, for each agent, randomly select a budget of virtual money at the beginning of time. When the social planner can elicit cardinal preferences, we prove that under a similar regularity assumption, incentive compatible and Pareto efficient mechanisms coincide with spot menu of random budgets mechanisms. These are similar to spot mechanisms except that, at the beginning of time, each agent chooses within a menu, a distribution over budget of virtual money

Financement local pour le climat global? Impact d'un programme d'efficacité énergétique local sur la consommation d'énergie et la création d'emplois

Subsidy programs for home energy retrofits are a popular tool to reduce CO2 emissions. Should they be implemented at the national level to leverage economies of scale or at the local level to more finely identify the best opportunities? To examine this question, we evaluate a program introduced in the French department of Essonne and compare its performance to that of its national counterparts. In a difference-in-differences framework, we identify a 8% reduction in residential natural gas use induced by the program, implying a carbon abatement cost of €44/tCO2eq. In a triple-difference framework, we further identify a 27% increase in employment in the renovation sector in Essonne, as opposed to non-renovation sectors and neighboring departments, implying about 20 jobs created per million euro spent. Looking more carefully at contractors' origin, we find that households were more likely to hire an Essonian firm than an equally distant one based outside Essonne. Altogether, our results suggest that local programs perform better than their national counterparts, and that a fair share of their benefits are retained locally. This calls for a stronger involvement of local authorities in managing home renovation policies

Log-normal Mutations and their Use in Detecting Surreptitious Fake Images

International audienceIn many cases, adversarial attacks against fake detectors employ algorithms specifically crafted for automatic image classifiers. These algorithms perform well, thanks to an excellent ad hoc distribution of initial attacks. However, these attacks are easily detected due to their specific initial distribution. Consequently, we explore alternative black-box attacks inspired by generic black-box optimization tools, particularly focusing on the log-normal algorithm that we successfully extend to attack fake detectors. Moreover, we demonstrate that this attack evades detection by neural networks trained to flag classical adversarial examples. Therefore, we train more general models capable of identifying a broader spectrum of attacks, including classical black-box attacks designed for images, black-box attacks driven by classical optimization, and no-box attacks. By integrating these attack detection capabilities with fake detectors, we develop more robust and effective fake detection systems

Daniel WALDENSTRÖM Richer and More Equal : A New History of Wealth in the West Cambridge, Polity, 2024, 256 pages (Note de lecture)

Note de lecture sur l'ouvrage de Daniel WALDENSTRÖM Richer and More Equal : A New History of Wealth in the West Cambridge, Polity, 2024, 256 page

Transport policy at an impasse: managing on-street delivery areas in Paris

International audienc

Optimizing Resource Allocation and Scheduling towards FRMCS and GSM-R networks coexistence in Railway Systems

International audienceThe actual railway communication system used in Europe for high-speed trains (HST) is called the GSM-R system, which is a communication system based on 2G infrastructure. This system is meant to be replaced by a new system based on 5G NR infrastructure called the Future Railway Mobile Communication System (FRMCS) by 2030. For the next years, both systems will probably coexist in the same frequency band since the migration from GSM-R to FRMCS is planned to be done progressively until the GSM-R system is completely shut down, mainly due to safety and budget constraints. In this paper, we study the resource allocation for the FRMCS system sharing the same frequency band as the already deployed GSM-R system. We formulate the resource allocation problem as an integer linear problem (ILP), known to be NP-hard.To solve it in a reasonable time, we propose a scheduling algorithm, called Intelligent Traffic Scheduling Preemptor (ITSP), that allocates resources for the different FRMCS traffic types considered (critical traffic and performance traffic) in the same frequency band with the GSM-R system. Our algorithm is channel quality Indicator (CQI) aware and uses the preemption mechanism in 5G NR standards to optimize the resource allocation for the FRMCS system without impacting the actual GSM-R resource allocation in the context of the white space concept