Mohamed Bahlali

Postdoctoral fellow ,  Aix-Marseille Université , Faculté d'économie et de gestion (FEG)

Public economics
Bahlali
Status
Postdoctoral fellow
Research domain(s)
Environmental economics
Thesis
2023, Paris-Dauphine University
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CV
Contact
mohamed.bahlali[at]univ-amu.fr
Address

AMU - AMSE
5-9 Boulevard Maurice Bourdet, CS 50498
​13205 Marseille Cedex 1

Website
https://sites.google.com/chaireeconomieduclimat.org/mohamed-bahlali/
Abstract Urban low-emission zones (LEZs) are increasingly used to reduce transportrelated air pollution, yet little is known about their long-run general equilibrium effects on the urban spatial structure and their implications in term of pollution exposure. To explore this question, we develop a quantitative spatial equilibrium model with endogenous commuting, transport mode choice and air pollution generated by transport, housing and firms activity. Pollution dispersion is described by an advection-diffusion equation accounting for atmospheric diffusion, deposition, and wind. We apply the model to the Grand Paris Low-Emission Zone and evaluate a long-run counterfactual in which internal combustion engine vehicles are banned from commuting within or through the regulated area. The results show that the policy substantially reduces car use and transport-related emissions. However, endogenous relocation by workers and firms partly offsets environmental gains by shifting economic activity and commuting flows toward more car-dependent peripheral areas, while simultaneously attenuating welfare losses. As a result, partial-equilibrium approaches that abstract from spatial reorganization tend to overestimate both the environmental benefits and welfare costs of the LEZ policy.
Keywords General equilibrium effects, Low-emission zones, Air pollution, Transport policies, Quantitative spatial equilibrium
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Abstract We propose a mean-field game (MFG) set-up to study the dynamics of spatial agglomeration in a continuous space-time framework where trade across locations may follow a broad class of static gravity models. Forward-looking intertemporal utility-maximizing agents work and migrate in a twodimensional geography and face idiosyncratic shocks. Equilibrium wages and prices depend on their common distribution and adjust statically according to the underlying trade model. We first prove existence and uniqueness of the static trade equilibrium. We then prove existence of dynamic equilibria. In the case of Krugman (1996)'s racetrack economy, we obtain closed-form solutions for small sinusoidal perturbations around the steady state, and we identify the sets of parameters that lead to agglomeration or dispersion. We exploit the MFG structure of the model to explicitly quantify how uncertainty and forward-looking expectations contribute to agglomeration and dispersion. In particular, we show that, regardless of the static trade model, forward-looking expectations always promote agglomeration, but cannot reverse the dominant pattern that would arise under myopic behavior.
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Abstract We propose a mean-field game (MFG) set-up to study the dynamics of spatial agglomeration in a continuous space-time framework where trade across locations may follow a broad class of static gravity models. Forward-looking intertemporal utility-maximizing agents work and migrate in a twodimensional geography and face idiosyncratic shocks. Equilibrium wages and prices depend on their common distribution and adjust statically according to the underlying trade model. We first prove existence and uniqueness of the static trade equilibrium. We then prove existence of dynamic equilibria. In the case of Krugman (1996)'s racetrack economy, we obtain closed-form solutions for small sinusoidal perturbations around the steady state, and we identify the sets of parameters that lead to agglomeration or dispersion. We exploit the MFG structure of the model to explicitly quantify how uncertainty and forward-looking expectations contribute to agglomeration and dispersion. In particular, we show that, regardless of the static trade model, forward-looking expectations always promote agglomeration, but cannot reverse the dominant pattern that would arise under myopic behavior.
Download HAL Google Scholar