Postdoctoral Position in (Urban) Economics/Applied Econometrics for 1 year (renewable) in DIJON (FRANCE)

Research Context

Climate change is increasing the frequency, intensity, and duration of heat waves (IPCC, 2023), regardless of the climate scenario considered. By 2050, it is estimated that the number of heatwave days will have doubled in France. Urban environments exacerbate these heatwaves through the heat island phenomenon, caused by a combination of several factors (urban morphology, anthropogenic heat, and specific urban surfaces). Additionally, climate change encourages the formation of certain pollutants, such as ozone (Masson et al., 2020), and increases concentrations of fine particles (Tai et al., 2010), both of which have significant health impacts (Soares and Silva, 2022; WHO, 2014). 

Climate change adaptation operates on two interdependent levels: urban public policy (involving adaptation of buildings, urban cover, and transportation) and individual adaptation (including changes in working hours, air conditioning use, and seeking cool zones or moving to new residential areas). However, these individual adaptations can increase greenhouse gas (GHG) emissions and particulate matter (PM2.5), worsening the climate crisis. Furthermore, these solutions create inequalities, as the most vulnerable households are often the most exposed (Morelli et al., 2019) and have the least capacity to adapt (Bourret Soto and Guillon, 2024). 

While several studies have explored the effects of air pollution on residential location using natural experiments (Pan, 2023; Banzhaf and Walsh, 2008) or instrumental variables (Freeman, 2019), there is little research on the effects of temperatures and heatwaves on residential mobility. It is reasonable to hypothesize that as heatwave summers become more frequent, urban residents may factor heat islands into their residential location decisions, seeking cooler environments for protection during the summer.

The postdoctoral project aims to document the effects of climate change—particularly heatwaves and air pollution—on residential mobility. Adaptation strategies linked to residential mobility, their impacts on urban and rural space organization, and their contribution to GHG and pollutant emissions remain poorly understood. The postdoctoral researcher will work to quantify the effects of these changes on population distribution and the impact of residential mobility on daily mobility, including transport modes and travel volumes. Based on this analysis, the researcher will estimate the emissions inventories (PM2.5, ozone, and GHG) altered by residential mobility and evolving daily travel patterns.

The Grenoble metropolitan area will serve as the first case study for this methodology, which will later be extended to other major urban areas in the Auvergne-Rhône-Alpes region and across France.

This postdoctoral project, which is part of two ongoing projects (ANR Clim’air, focusing on the economic and health assessment of climate change adaptation scenarios), and ClimZU submitted to the ANR PEPR TRACCS in September 2024, focusing on the modelling of temperatures during heat waves and the impact of these temperatures on mobility), offers an exciting opportunity to engage in interdisciplinary research at the intersection of climate adaptation, urban planning, and environmental economics. 

MISSIONS

Research questions

The PostDoc will address the following research questions:

• Which populations migrate (in terms of spatial and socio-economic characteristics) and to which destinations? What is the impact of air pollution and heatwaves on residential migration? 
• How does residential migration impact travel patterns, particularly car dependency and travel volumes from the urban periphery (suburbs and rural areas) to the urban center? 
• What impact does residential migration have on socio-spatial inequalities (e.g., spatial segregation)?

Phases of work

The postdoctoral researcher will:

1- Conduct a literature review (2 months)

The first stage will involve conducting a literature review on the links between residential location and pollution/climate to identify i) the types of pollutants that affect residential location; ii) whether there are thresholds above which air pollution induces residential mobility; iii) triggers for mobility (e.g., health events, the birth of a child); iv) the heterogeneity of households that can afford to move. The review could also turn to the few urban economy models that explore the connection between climate and urban sprawl. This will enable hypotheses to be formulated and tested. Depending on the researcher’s interests and skills, the postdoc will also review causal inference methods (e.g., difference-in-difference, synthetic control - Abadie et al., 2010), agent-based models or urban economy models taking into account climate amenities and pollution.

2- Quantify and analyze residential migration in major cities of the Auvergne-Rhône-Alpes region, using census data and post office mail redirection data.

The first empirical task will be to document and quantify residential migration in the major metropolitan areas of the Auvergne Rhône-Alpes region, including Grenoble. This involves a static analysis documenting changes in the population structures of central cities and their suburbs using census data, followed by a dynamic analysis focusing on migratory flows using the EDP, which makes it possible to identify the municipality of origin and the municipality of destination for the same person. Changes in migration flows will be compared with temperatures from Météo France in order to establish a possible correlation between pollution, heat waves and migration flows. Socio-spatial inequalities will also be documented in order to identify the types of household (income, stage of life) involved in mobility and the neighborhoods of origin of residential mobility, in spatial terms and in terms of the index of social disadvantage.

3-Apply causal inference models to establish the impact of heatwaves on residential mobility, considering other influencing factors like teleworking or housing preferences. 

The aim is to distinguish the causal effect of heat waves on residential migration from other factors, such as the widespread adoption of teleworking, or French people's growing preference for single-family homes, a trend that increased following the Covid-19 health crisis. Causal analysis could be conducted using a double-difference model or a synthetic control model, if possible generalised to take account for interactive fixed effects (Xu, 2017; Gobillon and Magnac, 2016). The main methodological challenge will be to form a control group, as heatwaves affect geographically close areas fairly uniformly. Depending on the methodology chosen, it may be beneficial to extend the analysis beyond Grenoble metropolitan area to the Alps, where greater temperature variation might offer opportunities for heterogeneity analysis (temperature fields and climatic data will be provided by the Clim’air project). It should be noted that no econometric analysis of the effects of pollution on residential migration is required.

4- Develop future scenarios for residential migration, taking into account projected climate changes and urban planning trends

This phase will simulate the future effects of climate change on the regional structuring. Residential migration scenarios will be developed based on literature reviews, quantification and characterisation of flows and econometric estimates. The aim is to project the results observed in the past into the future climate and the results of the causal inference according to a scenario that is plausible in the light of the urban planning projects but sufficiently contrasted to provide tangible elements for discussion for public policies. 

Depending on the postdoc’s skills and interests, three methods are proposed:

• A gravity model, assuming attractiveness is a function of temperature and property prices, with migratory flows structured according to temperature modeling.
• An agent-based model, accounting for city structure, as explored by Olner et al. (2015), Lemoy et al. (2017), and Schindler and Caruso (2020).

An urban economy model with simulations of temperature effects, inspired by models that introduce amenities (Cavailhes et al., 2014; Gaigne et al., 2019), possibly with a dynamic structure (Ahlfeldt et al., 2021).If options 2 or 3 are chosen, the time and expectations for causal inference (Step 3) will be greatly reduced. This stage will be strongly interdisciplinary, incorporating temperature and pollution modeling results from physicists and climatologists. The scenario could also be discussed with epidemiologists to assess its health impact.

5- Simulate the effects of migration on daily mobility. 

The final task will be to simulate the effects of household relocation (and therefore the structure of the city and its suburbs) on travel. To do this, the Grenoble metropolitan authority is providing us with the Visum multimodal transport model for the Grenoble region. By changing some of the model's input parameters (population and population structure by municipality, for example), it is possible to simulate the resulting travel volumes and their allocation on the network. This work will then be used to simulate a new emissions register (GHG, PM2.5). 

The scenarios on residential migrations and the simulation of daily mobility will serve as inputs for pollution emission inventories (ATMO Aura), health impact assessment (INSERM) and economic assessment (INRAE, CNRS). 

Data made available to the post-doc:

Permanent Demographic Sample (EDP), population census, SPAZM Météo France temperature data, temperature and pollution data modelled as part of the Mobil’air project on the Grenoble metropolitan area, town planning documents and interviews already conducted with the metropolitan area, the transport authority and the town planning agency to discuss current trends in population movements. 

Required Qualifications and Skills

• PhD in Economics
• Expertise in modeling and/or econometrics, with a strong interest in data processing
• Proficiency in statistical tools (at least one of the following software/languages: Stata, R, Python)
• Familiarity with agent-based models, skills in GIS and/or experience with Visum software would be a plus
• An interest in understanding climatic and physical processes

Working Conditions

The postdoctoral researcher will have the option to work remotely up to 2 days per week

The salary is between €2640 and €4540 per month and depends on the candidate’s experience. For reference, the INRAE salary scale is available at the following link: https://jobs.inrae.fr/actualites/remuneration-agents-contractuels

Recruitment Process

Candidates must send a cover letter, a CV, Master’s transcripts, and one or two representative documents (published article or working paper) demonstrating their qualifications and experience, as well as a letter of recommendation and the contact details of two referees to: marie.breuille@inrae.fr, helene.bouscasse@inrae.fr, and sandrine.mathy@univ-grenoble-alpes.fr.

Shortlisted candidates will be invited for an interview. The position will remain open until November 25th.

For any questions, please contact Hélène Bouscasse (helene.bouscasse@inrae.fr) or Marie Breuillé (marie.breuille@inrae.fr).