Working papers

Abstract: This paper investigates the impacts of several implementations of daily mobility policies and external shocks on social costs, with a particular focus on carpooling. This social cost is calculated considering consumer's cost, external costs, as well as the expenses and incomes of public authorities and private companies. Four transport modes are considered: solo driver, carpool driver, carpool passenger and public transport. A modal choice model is then applied to trips with 6,287 different origin-destination of the eastern Lyon area. Simulations of time-gain and monetary scenarios are then realized to observe impacts on demand and consequently on the other parameters affecting the social costs. Our results show that consumer's costs explain the majority of the total social cost. Values commonly used for externalities barely impact the social cost in the simulations and traffic reduction measures impact more public and private revenues than they reduce externalities, leading to higher total social costs. Moreover, results illustrate significant variations at the geographical scale, depending on the ODs where the policies are applied. These results suggest implementing daily-carpooling incentives should be decided conscientiously considering the local context. 

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Abstract: This paper investigates the effects of carpooling organization and individuals’ idiosyncrasies on the propensity to carpool. We test whether pre-planning the trip, use of a platform, and socio-demographic similarities or differences between driver and passenger affect choices towards carpooling over solo-driving and public transportation. A stated choice experiment collected answers of 3,600 inhabitants from in the Lyon’s urban area, France. Our results indicate platforms raise the individual willingness to carpool, and that this platform’s effect is larger for passengers than for drivers. Other things being equal, we identify a clear gender effect: women are more easily accepted as carpoolers than men, and they also are more sensible than men to their carpooler’s gender. By contrast, the age of the proposed carpooler does not affect carpooling choices. We illustrate these results with a stylized social welfare analysis which highlights a significant contradiction between what it would take to make carpooling beneficial from a welfare perspective – drivers should pay passengers – and what seems to be individually acceptable. 

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Abstract: This paper investigates pricing decisions when a monopolistic multi-sided platform is myopic, that is unable to distinguish between two agents who participate on the same side of the platform but produce different externalities. We find that the structure of prices is the same for profit- and welfare-maximizing platforms. The unique price supplied to the two undistinguishable agents is a weighted average of the perfect information prices, where the weights depend on demand elasticities and externalities produced by the other undistinguishable agent. The prices supplied to the distinguishable agents are also affected by information asymmetry through an extra term than can be positive or negative. Introducing Hotelling competition does not affect results. We apply the model to a monopolistic short-distance carpooling platform with and without HOV lane, and show that the profit-maximizing platform does not subsidize efficiently the “good” side of the market, leading to very little traffic reduction. These results call for a discussion of the regulation of myopic platforms in general, and those of carpooling in particular. 

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