Titre de la thèse : Inégalités au niveau communal, changement climatique et migration locale au Chili
Sous la direction de Matthieu Clement et de Pierre Levasseur
Thèses en préparation à Bordeaux , dans le cadre de École doctorale Entreprise, économie, société (Pessac, Gironde ; 1991-....) , en partenariat avec BSE - Bordeaux sciences économiques (laboratoire) depuis le 27-08-2021 .
Résumé : Le Chili est un pays connu pour ses niveaux élevés d'inégalité par rapport à la région. Selon la Banque mondiale, le coefficient de Gini du revenu total au Chili a régulièrement diminué ces dernières années. Il est passé d'un maximum de 0,572 en 1990 à un minimum de 0,444 en 2015, avec une légère augmentation observée en 2020, atteignant 0,449. Malgré ceci, il est intéressant de noter que lorsque nous examinons l'inégalité basée sur le travail ou le revenu autonome (sans tenir compte des transferts de l'Etat), le coefficient de Gini reste remarquablement stable. Cependant, les études négligent souvent l'inégalité mesurée à des niveaux territoriaux plus restreints, tels que les communes. Le manque d'informations représentatives sur le revenu à une petite échelle spatiale pose un défi majeur dans l'étude de l'inégalité au niveau communal. En effet, au Chili, les données fiables sur le revenu ne sont représentatives qu'au niveau national et régional. En conséquence, afin de combler cette lacune, on utilise le modèle d'estimation de Small Area Estimation proposé par Elbers, Lanjouw et Lanjouw (2003), également connu sous le nom de modèle ELL, pour générer des indicateurs représentatifs de la répartition des revenus au niveau municipal. L'objectif est d'analyser d'abord l'inégalité au niveau territorial et d'identifier les variables qui contribuent le plus aux niveaux plus élevés d'inégalité dans les territoires supposés être plus homogènes. Compte tenu du territoire chilien hautement hétérogène en termes de climat et de caractéristiques géologiques, nous mènerons cette analyse à travers le prisme du changement climatique, qui affecte chaque région du pays de manière différente. Le changement climatique constitue l'un des défis les plus graves pour le monde et ses habitants. Ses perturbations sont devenues une menace croissante qui dégrade la qualité de l'air, limite l'accès à l'eau et à la nourriture, et exerce une pression sur les espaces habitables. Cependant, le changement climatique n'affecte pas tout le monde de la même manière, les groupes sociaux les plus vulnérables étant actuellement les plus exposés aux risques. Ainsi, le changement climatique est également une question de justice environnementale. Au cours de la dernière décennie, il y a eu un intérêt croissant dans le domaine de la recherche pour étudier comment différents indicateurs du changement climatique (tels que la température, les précipitations et les tempêtes) peuvent influencer les résultats économiques (Dell et al., 2014). Cependant, il existe très peu d'études qui tentent de relier les risques environnementaux aux inégalités, et la plupart d'entre elles se concentrent sur des preuves à l'échelle macro en utilisant des données transnationales. Parmi leurs conclusions, on observe une relation en forme de U inversé entre la température et la productivité économique globale, avec un pic de productivité à une température moyenne annuelle de 13°C, puis une forte diminution à des températures plus élevées (Burke et al., 2015). De plus, un effet positif a été constaté entre le changement climatique et l'inégalité économique entre les pays, du fait que le réchauffement à long terme augmentera généralement la croissance dans les pays froids et diminuera la croissance dans les pays chauds (Diffenbaugh et Burke, 2019). Des preuves montrent également que la volatilité climatique actuelle a accru la pauvreté dans un échantillon de pays en développement, en particulier au Bangladesh, au Mexique, en Indonésie et en Afrique, les travailleurs urbains étant le groupe le plus vulnérable (Ahmed et al., 2009). Des niveaux plus élevés d'inégalité des revenus (mesurés par l'indice de Gini) sont associés à un plus grand nombre de personnes touchées par les catastrophes naturelles. Dans certains endroits, les catastrophes naturelles déclenchent un cercle vicieux qui aggrave l'inégalité précédente, ce que les auteurs appellent le "disaster-inequality trap" (Cappelli et al., 2021). Les chocs climatiques et les catastrophes ont également un impact négatif sur l'égalité des sexes, associé à une diminution des droits économiques et sociaux des femmes (Eastin, 2018). Enfin, en utilisant des données mondiales, régionales et des ménages provenant de l'Afrique du Sud et une méthodologie des premières différences, la seule étude (à notre connaissance) qui a étudié l'impact du changement climatique sur l'inégalité des revenus et la pauvreté à l'intérieur d'un pays, a établi une relation significative en forme de U entre l'inégalité et les indicateurs de pauvreté et la température moyenne locale (Dasgupta et al., 2020). Cependant, la principale limitation de cette étude réside dans la sous-estimation importante de la distribution des revenus, due à l'utilisation de données économiques par grille. Motivé par cette lacune dans la littérature, ce projet aborde la question du changement climatique en tant que vecteur d'injustice environnementale au Chili. Plus précisément, nous cherchons à identifier empiriquement l'impact de l'exposition au changement climatique sur les inégalités de revenus au niveau municipal, afin de proposer des recommandations de politiques publiques visant non seulement à atténuer le changement climatique, mais aussi à réduire la vulnérabilité des plus pauvres.
Titre traduit : Communal level inequality, climate change and local migration in Chile
Summary: Chile is a country known for its high levels of inequality compared to the region. According to the World Bank Data Base, Chile's Gini coefficient of total income has consistently decreased in recent years. It went from a maximum of 0.572 in 1990 to a minimum of 0.444 in 2015, with a slight increase observed in 2020, reaching 0.449. Interestingly, when we examine inequality based on work or autonomous income (without considering state transfers), the Gini coefficient remains notably stable. However, studies often overlook inequality measured at smaller territorial levels such as communes. The lack of representative information on income at a small spatial scale poses a major challenge in studying inequality at the communal level. Indeed, in Chile, reliable income data is only available at the national and regional levels. So, to address this gap, we aim to employ the unit-level small area estimation model proposed by Elbers, Lanjouw & Lanjouw (2003), also known as the ELL model, to generate representative indicators of income distribution at the municipal level. The objective is to first analyze inequality at the territorial level and identify the variables that contribute most to higher levels of inequality in territories that are presumed to be more homogeneous. Given Chile's highly heterogeneous territory in terms of climate and geological characteristics, we will conduct this analysis through the lens of climate change, which affects each region of the country differently. Climate change presents one of the most serious challenges to the world and its people. Its disruptions have increasingly become a global threat, degrading air quality, limiting access to water and food, and exerting pressure on habitable spaces. However, climate change does not impact everyone equally, with the most vulnerable social groups currently facing the greatest risks. Thus, climate change is also an issue of environmental justice. Over the past decade, there has been a growing interest in the research field to study how different climate change indicators (such as temperature, precipitation and windstorms) can influence economic outcomes (Dell et al., 2014). However, there are very few studies attempting to link environmental hazards with inequality, and most of them focus on macro-level evidence using cross-country data. Among their findings, an inverted u-shaped relationship is observed between temperature and overall economic productivity, with productivity peaking at an annual average temperature of 13°C and strongly declining at higher temperatures (Burke et al., 2015). Also, a positive effect was found between climate change and economic inequality between countries, caused by the fact that long-term warming will generally increase growth in cool countries and decrease growth in warm countries (Diffenbaugh & Burke, 2019). Evidence also shows that present climate volatility increased poverty across a developing country sample—particularly in Bangladesh, Mexico, Indonesia, and Africa—with urban wage earners being the most vulnerable group (Ahmed et al., 2009). Higher levels of income inequality (measured by the Gini index) are associated with more people affected by natural disasters. Natural disasters on some locations trigger a vicious-cycle, deepening the previous inequality, what the authors called the “disaster-inequality trap” (Cappelli et al., 2021). Climate shocks and disasters also show to exert a negative impact on gender equality, associated with declines in women's economic and social rights (Eastin, 2018). Finally, using global, regional and household panel data from South Africa and a first differences methodology, the only paper (to our knowledge) which has studied the impact of climate change on within-country income inequality and poverty, established a significant u-shaped relationship between inequality and poverty indicators and local mean temperature (Dasgupta et al., 2020). However, this study's main limitation is the heavily underestimated income distribution, coming from the use of gridded economic activity data. Motivated by this gap in the literature, this project addresses the issue of climate change as a vector of environmental injustice in Chile. More specifically, we seek to identify empirically the impact of climate change exposure on income inequalities at the municipal level, in order to propose public policy recommendations aimed not only at mitigating climate change but also at decreasing the vulnerability of the poorest.
Titre traduit : Communal level inequality, climate change and local migration in Chile
Summary: Chile is a country known for its high levels of inequality compared to the region. According to the World Bank Data Base, Chile's Gini coefficient of total income has consistently decreased in recent years. It went from a maximum of 0.572 in 1990 to a minimum of 0.444 in 2015, with a slight increase observed in 2020, reaching 0.449. Interestingly, when we examine inequality based on work or autonomous income (without considering state transfers), the Gini coefficient remains notably stable. However, studies often overlook inequality measured at smaller territorial levels such as communes. The lack of representative information on income at a small spatial scale poses a major challenge in studying inequality at the communal level. Indeed, in Chile, reliable income data is only available at the national and regional levels. So, to address this gap, we aim to employ the unit-level small area estimation model proposed by Elbers, Lanjouw & Lanjouw (2003), also known as the ELL model, to generate representative indicators of income distribution at the municipal level. The objective is to first analyze inequality at the territorial level and identify the variables that contribute most to higher levels of inequality in territories that are presumed to be more homogeneous. Given Chile's highly heterogeneous territory in terms of climate and geological characteristics, we will conduct this analysis through the lens of climate change, which affects each region of the country differently. Climate change presents one of the most serious challenges to the world and its people. Its disruptions have increasingly become a global threat, degrading air quality, limiting access to water and food, and exerting pressure on habitable spaces. However, climate change does not impact everyone equally, with the most vulnerable social groups currently facing the greatest risks. Thus, climate change is also an issue of environmental justice. Over the past decade, there has been a growing interest in the research field to study how different climate change indicators (such as temperature, precipitation and windstorms) can influence economic outcomes (Dell et al., 2014). However, there are very few studies attempting to link environmental hazards with inequality, and most of them focus on macro-level evidence using cross-country data. Among their findings, an inverted u-shaped relationship is observed between temperature and overall economic productivity, with productivity peaking at an annual average temperature of 13°C and strongly declining at higher temperatures (Burke et al., 2015). Also, a positive effect was found between climate change and economic inequality between countries, caused by the fact that long-term warming will generally increase growth in cool countries and decrease growth in warm countries (Diffenbaugh & Burke, 2019). Evidence also shows that present climate volatility increased poverty across a developing country sample—particularly in Bangladesh, Mexico, Indonesia, and Africa—with urban wage earners being the most vulnerable group (Ahmed et al., 2009). Higher levels of income inequality (measured by the Gini index) are associated with more people affected by natural disasters. Natural disasters on some locations trigger a vicious-cycle, deepening the previous inequality, what the authors called the “disaster-inequality trap” (Cappelli et al., 2021). Climate shocks and disasters also show to exert a negative impact on gender equality, associated with declines in women's economic and social rights (Eastin, 2018). Finally, using global, regional and household panel data from South Africa and a first differences methodology, the only paper (to our knowledge) which has studied the impact of climate change on within-country income inequality and poverty, established a significant u-shaped relationship between inequality and poverty indicators and local mean temperature (Dasgupta et al., 2020). However, this study's main limitation is the heavily underestimated income distribution, coming from the use of gridded economic activity data. Motivated by this gap in the literature, this project addresses the issue of climate change as a vector of environmental injustice in Chile. More specifically, we seek to identify empirically the impact of climate change exposure on income inequalities at the municipal level, in order to propose public policy recommendations aimed not only at mitigating climate change but also at decreasing the vulnerability of the poorest.
