Research

Publications

Does Carpooling Reduce Carbon Emissions? The Effect of Environmental Policies in France (w/ Maïté Stephan, Alexandre Volle, and Dianzhuo Zhu) Environmental & Resource Economics, Feb. 2025. https://doi.org/10.1007/s10640-025-00962-6

Abstract
Road transportation is among the most carbon-intensive sectors in the economy, underscoring the urgent need for strategies to meet climate objectives. Carpooling has emerged as a promising solution for carbon mitigation. However, by making car travel more attractive, carpooling may lead to ambiguous environmental outcomes. This study evaluates carpooling’s potential to mitigate carbon emissions and explores various strategies to enhance its environmental benefits. A key focus of this research is the vehicle occupancy rate, which we define as a robust metric for assessing carpooling’s carbon mitigation potential. This metric is reliable as it accounts for travelers’ preferences for alternative transport modes. We also analyze how policies that impact monetary trip costs influence carpooling adoption. Using a unique database from France’s leading carpooling platform, we show that increasing monetary trip costs through carbon pricing boosts both carpooling demand and supply, while improving occupancy rates. Furthermore, we find that novice users are particularly sensitive to fluctuations in monetary trip costs. In addition to this policy, we explore the effect of encouraging drivers to transition into passengers. Our results suggest that this strategy holds significant potential for further reducing carbon emissions. The insights from this study are crucial for policymakers seeking to design more effective strategies for reducing vehicle emissions and achieving climate targets.

Working Papers

Harmonizing Dockless E-scooters: Insights from Paris (w/ Eric Brousseau, Etienne Côme, and Nicolas Coulombel) Available at SSRN

Abstract
Improper parking is one of the most significant barriers to the adoption and acceptance of dockless shared e-scooters worldwide. This paper investigates the effects of mandatory parking regulations that require e-scooters to be parked in designated bays in the form of painted corrals in Paris. To assess the impact of these regulations and their unintended effects, we develop a novel multicriteria evaluation method around three principles: efficiency, accessibility, and compliance. Using a unique large-scale database that geolocates every parked e-scooter in the city at three-hour intervals, we find that designated parking bays reduce cluttering and mis-parking. However, they also unintentionally reduce accessibility. Furthermore, we provide insights into the persistence of mis-parking and the congestion of parking bays, two key factors that contributed to the ban of shared e-scooters in the city.
Fire Bikes to the Rescue! Bike-Sharing and Public Transport Substitution Link to the manuscrit

Abstract
The introduction of new mobility services, such as bike-sharing, has profoundly transformed urban mobility. These services have been adopted for their potential to improve efficiency, reduce congestion, and lower pollution by enhancing complementarities with public transport. However, the market dynamics between new services and public transport remains unclear. This study leverages a natural experiment based on an extemporaneous incident that temporarily shut down operations in Mexico City’s subway network. Using geolocation data to analyze the spatial relationship between bike-sharing and subway stations, I identify bike journeys that substitute or complement public transport. The evidence suggests a substantial increase in the degree of substitution to bike-sharing during subway disruptions. Furthermore, following the restoration of subway service, both overall demand for bike-sharing and its complementarity with public transit increase. Lastly, I present evidence suggesting that this expansion is associated with a rise in subway ridership. These findings have important implications for the future of urban mobility, providing robust empirical insights for developing a resilient, efficient, and sustainable transport system.
Contract Shifting vs Contract Splitting in Public Procurement (w/ Juan Ivars) Link to the manuscrit

Abstract
This paper investigates the consequences of prohibiting discretion in public procurement. We study whether procurement officials manipulate the estimated value of contracts to avoid crossing regulatory thresholds and how this impacts procurement outcomes. We exploit the unique design of the procurement law in Colombia to document three empirical findings. First, there is substantial manipulation of contracts around the threshold. Second, manipulation occurs in two different forms: contract shifting and contract splitting. Contract shifting means decreasing the estimated value of the contract while contract splitting refers to dividing a contract into multiple smaller parts. We show that contract shifting is the main form of manipulation in this context. Third, manipulation decreases the final value paid and does not affect the number of bidders or the frequency of repeated winners. However, manipulation decreases the quality of the procedure. We propose a model of public procurement that explains when each type of manipulation is used and outlines its welfare implications. We find that procurers promote contract shifting when they face small purchase thresholds and contract splitting when they face large ones. Conversely, the model shows that contract splitting is welfare-enhancing for small thresholds and decreasing for large ones. Contract shifting is always welfare-enhancing. We conclude by discussing the policy implications.

Work in Progress

Sharing Rules in Renewable Energy Communities: A Review of the Literature (w/ Marco Gazel and Julien Jacqmin)
Default Sharing Rule and the Slow Take-up of Renewable Energy Communities in France (w/ Marco Gazel and Julien Jacqmin)
Simple Auctions to Boost Green Public Procurement: Evidence from Colombia (w/ Carine Staropoli)
Pooled, not Scrambled! Harmonizing Digital Mobility Platforms (w/ Eric Brousseau)