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Fields of Specialization
Green growth, Climate change, Urban development
Externally Hosted Work
Last updated September 13, 2023
Stéphane Hallegatte is a Senior Climate Change Adviser at the World Bank. He joined the World Bank in 2012 after 10 years of academic research in environmental economics and climate science for Météo-France, the Centre International de Recherche sur l’Environnement et le Développement, and Stanford University. His research interests include the economics of natural disasters and risk management, climate change adaptation, urban policy and economics, climate change mitigation, and green growth. Mr. Hallegatte was a lead author of the 5th Assessment Report of the Intergovernmental Panel on Climate Change (IPCC). He is the author of dozens of articles published in international journals in multiple disciplines and of several books, including Green Economy and the Crisis: 30 Proposals for a More Sustainable France , Risk Management: Lessons from the Storm Xynthia , and Natural Disasters and Climate Change: An Economic Perspective . He also co-led the World Bank reports Inclusive Green Growth: The Pathway to Sustainable Development , published in 2012 and Decarbonizing Development in 2015, and was member of the core writing team of the 2014 World Development Report Risk and Opportunity: Managing Risks for Development . Most recently, he led the World Bank reports Shock Waves: Managing the Impacts of Climate Change on Poverty , Unbreakable: Building the Resilience of the Poor in the Face of Natural Disasters , and Lifelines: the Resilient Infrastructure Opportunity. He was the team leader for the World Bank Group Climate Change Action Plan, a large internal coordination exercise to determine and explain how the Group will support countries in their implementation of the Paris Agreement. Mr. Hallegatte holds engineering degrees from the Ecole Polytechnique (Paris) and the Ecole Nationale de la Météorologie (Toulouse), a master's degree in meteorology and climatology from the Université Paul Sabatier (Toulouse) and a Ph.D in economics from the Ecole des Hautes Etudes en Sciences Sociales (Paris).
Publication Search Results
Now showing 1 - 10 of 17
Publication(World Bank, Washington, DC, 2019-01) Walsh, Brian ; Hallegatte, StephaneTraditional risk assessments use asset losses as the main metric to measure the severity of a disaster. This paper proposes an expanded risk assessment based on a framework that adds socioeconomic resilience and uses wellbeing losses as its main measure of disaster severity. Using a new, agent-based model that represents explicitly the recovery and reconstruction process at the household level, this risk assessment provides new insights into disaster risks in the Philippines. First, there is a close link between natural disasters and poverty. On average, the estimates suggest that almost half a million Filipinos per year face transient consumption poverty due to natural disasters. Nationally, the bottom income quintile suffers only 9 percent of the total asset losses, but 31 percent of the total wellbeing losses. The average annual wellbeing losses due to disasters in the Philippines is estimated at US$3.9 billion per year, more than double the asset losses of US$1.4 billion. Second, the regions identified as priorities for risk-management interventions differ depending on which risk metric is used. Cost-benefit analyses based on asset losses direct risk reduction investments toward the richest regions and areas. A focus on poverty or wellbeing rebalances the analysis and generates a different set of regional priorities. Finally, measuring disaster impacts through poverty and wellbeing impacts allows the quantification of the benefits from interventions like rapid post-disaster support and adaptive social protection. Although these measures do not reduce asset losses, they efficiently reduce their consequences for wellbeing by making the population more resilient.
Publication(World Bank, Washington, DC, 2015-07) Hallegatte, StephaneThe welfare impact of a disaster does not depend only on the physical characteristics of the event or its direct impacts in terms of lost lives and assets. Depending on the ability of the economy to cope, recover, and reconstruct, the reconstruction will be more or less difficult, and the welfare effects smaller or larger. This ability, which can be referred to as the macroeconomic resilience of the economy to natural disasters, is an important parameter to estimate the overall vulnerability of a population. Here, resilience is decomposed into two components: instantaneous resilience, which is the ability to limit the magnitude of the immediate loss of income for a given amount of capital losses, and dynamic resilience, which is the ability to reconstruct and recover quickly. The paper proposes a rule of thumb to estimate macroeconomic resilience, based on the interest rate (a higher interest rate decreases resilience and increases welfare losses), the reconstruction duration (a longer reconstruction duration increases welfare losses), and a “ripple-effect” factor that increases or decreases immediate losses (negative if enough idle resources are available to cope; positive if cross-sector and supply-chain issues impair the production of non-affected capital). An optimal risk management strategy is very likely to include measures to reduce direct impacts (disaster risk reduction actions) and measures to reduce indirect impacts (resilience building actions).
Publication(Washington, DC: World Bank, 2015-06) Fay, Marianne ; Hallegatte, Stephane ; Vogt-Schilb, Adrien ; Rozenberg, Julie ; Narloch, Ulf ; Kerr, TomThe science is unequivocal: stabilizing climate change implies bringing net carbon emissions to zero. And this must be done by 2100 if we are to keep climate change anywhere near the 2 C. degree warming that world leaders have set as the maximum acceptable limit. Decarbonizing Development looks at what it would take to decarbonize the world economy by 2100 in a way that is compatible with countries’ broader development goals. It argues that the following are needed: Act early with an eye on the end-goal; Go beyond prices with a policy package that triggers changes in investment patterns, technologies and behaviors; Mind the political economy and smooth the transition for those who stand to be most affected.
Publication(World Bank, Washington, DC, 2015-11) Park, Jisung ; Hallegatte, Stephane ; Bangalore, Mook ; Sandhoefner, EvanRecent economic research documents a range of adverse welfare consequences from extreme heat stress, including health, labor productivity, and direct consumption disutility impacts. Without rapid adaptation, climate change will increase the burden of heat stress experienced by much of the world’s population in the coming decades. What will the distributional consequences of this added heat stress be, and how might this affect optimal climate policy? Using detailed survey data of household wealth in 690,745 households across 52 countries, this paper finds evidence suggesting that the welfare impacts of added heat stress caused by climate change may be regressive. Specifically, the analysis finds that poorer households tend to be located in hotter locations across and within countries, and poorer individuals are more likely to work in occupations with greater exposure to the elements not only across but also within countries. These findings—combined with the fact that current social cost of carbon estimates do not include climate damages arising from the productivity impacts of heat stress—suggest that optimal climate policy, especially when allowing for declining marginal utility of consumption, involves more stringent abatement than currently suggested, and that redistributive adaptation policies may be required to reduce the mechanical inequities in welfare impacts arising from climate change.
The Impacts of Climate Change on Poverty in 2030 and the Potential from Rapid, Inclusive, and Climate-Informed Development(World Bank, Washington, DC, 2015-11) Rozenberg, Julie ; Hallegatte, StephaneThe impacts of climate change on poverty depend on the magnitude of climate change, but also on demographic and socioeconomic trends. An analysis of hundreds of baseline scenarios for future economic development in the absence of climate change in 92 countries shows that the drivers of poverty eradication differ across countries. Two representative scenarios are selected from these hundreds. One scenario is optimistic regarding poverty and is labeled “prosperity;” the other scenario is pessimistic and labeled “poverty.” Results from sector analyses of climate change impacts—in agriculture, health, and natural disasters—are introduced in the two scenarios. By 2030, climate change is found to have a significant impact on poverty, especially through higher food prices and reduction of agricultural production in Africa and South Asia, and through health in all regions. But the magnitude of these impacts depends on development choices. In the prosperity scenario with rapid, inclusive, and climate-informed development, climate change increases poverty by between 3 million and 16 million in 2030. The increase in poverty reaches between 35 million and 122 million if development is delayed and less inclusive (the poverty scenario).
Publication(World Bank, Washington, DC, 2016-05) Hallegatte, Stephane ; Bangalore, Mook ; Vogt-Schilb, AdrienThis paper presents a model to assess the socioeconomic resilience to natural disasters of an economy, defined as its capacity to mitigate the impact of disaster-related asset losses on welfare, and a tool to help decision makers identify the most promising policy options to reduce welfare losses due to floods. Calibrated with household surveys, the model suggests that welfare losses from the July 2005 floods in Mumbai were almost double the asset losses, because losses were concentrated on poor and vulnerable populations. Applied to river floods in 90 countries, the model provides estimates of country-level socioeconomic resilience. Because floods disproportionally affect poor people, each $1 of global flood asset loss is equivalent to a $1.6 reduction in the affected country's national income, on average. The model also assesses and ranks policy levers to reduce flood losses in each country. It shows that considering asset losses is insufficient to assess disaster risk management policies. The same reduction in asset losses results in different welfare gains depending on who benefits. And some policies, such as adaptive social protection, do not reduce asset losses, but still reduce welfare losses. Asset and welfare losses can even move in opposite directions: increasing by one percentage point the share of income of the bottom 20 percent in the 90 countries would increase asset losses by 0.6 percent, since more wealth would be at risk. But it would also reduce the impact of income losses on wellbeing, and ultimately reduce welfare losses by 3.4 percent.
Macroeconomic Consequences of Natural Disasters: A Modeling Proposal and Application to Floods and Earthquakes in Turkey(Washington, DC: World Bank, 2022-02-22) Hallegatte, Stephane ; Jooste, Charl ; Mcisaac, Florent JohnTurkey is vulnerable to natural disasters that can generate substantial damages to public and private sector infrastructure capital. Earthquakes and floods are the most frequent hazards today, and flood risks are expected to increase with climate change. To ensure stability and growth and minimize the welfare impact of these disasters, these shocks need to be managed and accounted for in macro-fiscal and monetary policy. To support this process, the World Bank Macrostructural Model is adapted to assess the macroeconomic effects of natural (geophysical or climate-related) disasters. The macroeconomic model is extended on several fronts: (1) a distinction is made between infrastructure and non-infrastructure capital, with complementary or substitutability between the two categories; (2) the production function is adjusted to account for short-term complementarity across capital assets; (3) the reconstruction process is modeled in a way that accounts for post-disaster constraints, with distinct processes for the reconstruction of public and private assets. The results show that destroyed infrastructure capital makes the remaining non-infrastructure capital less productive, which means that disasters reduce the total stock of capital, but also its productivity. The welfare impact of a disaster—proxied by the discounted consumption loss—is found to increase non-linearly with direct asset losses. Macroeconomic responses reduce the welfare impact of minor disasters but magnify it when direct asset losses exceed the economy’s absorption capacity. The welfare impact also depends on the pre-existing economic situation, the ability of the economy to reallocate resources toward reconstruction, and the response of the monetary policy. Appropriate macro-fiscal and monetary policies offer cost-effective opportunities to mitigate the welfare impact of major disasters.
Publication(Washington, DC: World Bank, 2017) Hallegatte, Stephane ; Vogt-Schilb, Adrien ; Bangalore, Mook ; Rozenberg, Julie“Economic losses from natural disasters totaled $92 billion in 2015.” Such statements, all too commonplace, assess the severity of disasters by no other measure than the damage inflicted on buildings, infrastructure, and agricultural production. But $1 in losses does not mean the same thing to a rich person that it does to a poor person; the gravity of a $92 billion loss depends on who experiences it. By focusing on aggregate losses—the traditional approach to disaster risk—we restrict our consideration to how disasters affect those wealthy enough to have assets to lose in the first place, and largely ignore the plight of poor people. This report moves beyond asset and production losses and shifts its attention to how natural disasters affect people’s well-being. Disasters are far greater threats to well-being than traditional estimates suggest. This approach provides a more nuanced view of natural disasters than usual reporting, and a perspective that takes fuller account of poor people’s vulnerabilities. Poor people suffer only a fraction of economic losses caused by disasters, but they bear the brunt of their consequences. Understanding the disproportionate vulnerability of poor people also makes the case for setting new intervention priorities to lessen the impact of natural disasters on the world’s poor, such as expanding financial inclusion, disaster risk and health insurance, social protection and adaptive safety nets, contingent finance and reserve funds, and universal access to early warning systems. Efforts to reduce disaster risk and poverty go hand in hand. Because disasters impoverish so many, disaster risk management is inseparable from poverty reduction policy, and vice versa. As climate change magnifies natural hazards, and because protection infrastructure alone cannot eliminate risk, a more resilient population has never been more critical to breaking the cycle of disaster-induced poverty.
Publication(World Bank, Washington, DC, 2016-07) Rozenberg, Julie ; Hallegatte, StephaneThe impacts of climate change on poverty depend on the magnitude of climate change, but also on demographic and socioeconomic trends. An analysis of hundreds of baseline scenarios for future economic development in the absence of climate change in Vietnam shows that the main determinant of the eradication of extreme poverty by 2030 is the income of unskilled agriculture workers, followed by redistribution policies. Results from sector analyses of climate change impacts—in agriculture, health, and natural disasters—are introduced in each of the hundreds scenarios. By 2030 climate change is found to have a significant impact on poverty in Vietnam in about a quarter of the scenarios, with 400,000 to more than a million people living in extreme poverty just because of climate change impacts. Those scenarios in which climate change pushes the most people into poverty are scenarios with slow structural change away from agriculture, low productivity growth in agriculture, high population growth, and low redistribution levels. Conversely, in scenarios with rapid, inclusive, and climate-informed development, climate change has no impact on extreme poverty, although it still has an impact on the income of the bottom 40 percent.
Are Losses from Natural Disasters More Than Just Asset Losses?: The Role of Capital Aggregation, Sector Interactions, and Investment Behaviors(World Bank, Washington, DC, 2016-11) Hallegatte, Stephane ; Vogt-Schilb, AdrienThe welfare impact of a natural disaster depends on its effect on consumption, not only on the direct asset losses and human losses that are usually estimated and reported after disasters. This paper proposes a framework to assess disaster-related consumption losses, starting from an estimate of the asset losses, and leading to the following findings. First, output losses after a disaster destroys part of the capital stock are better estimated by using the average—not the marginal—productivity of capital. A model that describes capital in the economy as a single homogeneous stock would systematically underestimate disaster output losses, compared with a model that tracks capital in different sectors with limited reallocation options. Second, the net present value of disaster-caused consumption losses decreases when reconstruction is accelerated. With standard parameters, discounted consumption losses are only 10 percent larger than asset losses if reconstruction is completed in one year, compared with 80 percent if reconstruction takes 10 years. Third, for disasters of similar magnitude, consumption losses are expected to be lower where the productivity of capital is higher, such as in capital-scarce developing countries. This mechanism may partly compensate for the many other factors that make poor countries and poor people more vulnerable to disasters.