Person:
Hallegatte, Stéphane
Author Name Variants
Fields of Specialization
Green growth,
Climate change,
Urban development
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Last updated
December 4, 2023
Biography
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
1 - 10 of 57
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Publication
Floods and Their Impacts on Firms: Evidence from Tanzania
(World Bank, Washington, DC, 2021-09)This study explores how businesses in Tanzania are impacted by floods, and which strategies they use to cope and adapt. These insights are based on firm survey data collected in 2018 using a tailored questionnaire, covering a sample of more than 800 firms. To assess the impact of disasters on businesses, the study considers direct damages and indirect effects through infrastructure systems, supply chains, and workers. While direct on-site damages from flooding can be substantial, they tend to affect a relatively small share of firms. Indirect impacts of floods are more prevalent and sizable. Flood-induced infrastructure disruptions—especially electricity and transport—obstruct the operations of firms even when they are not directly located in flood zones. The effects of such disruptions are further propagated and multiplied along supply chains. The study estimates that supply chain multipliers are responsible for 30 to 50 percent of all flood-related delivery delays. To cope with these impacts, firms apply a variety of strategies. Firms mitigate supply disruptions by adjusting the size and geographical reach of their supply networks, and by adjusting inventory holdings. By investing in costly backup capacity (such as water tanks and electricity generators), firms mitigate the impact of infrastructure disruptions. The study estimates that only 13 percent of firms receive government support in the aftermath of floods. -
Publication
The Road to Recovery: The Role of Poverty in the Exposure, Vulnerability and Resilience to Floods in Accra
(World Bank, Washington, DC, 2018-06)In June 2015, about 53,000 people were affected by unusually severe floods in the Greater Accra Metropolitan Area, Ghana. The real impact of such a disaster is a product of exposure ("Who was affected?"), vulnerability ("How much did the affected households lose?"), and socioeconomic resilience ("What was their ability to cope and recover?"). This study explores these three dimensions to assess whether poor people were disproportionally affected by the 2015 floods. It reaches four main conclusions. (1) In the studied area, there is no difference in annual expenditures between the households who were affected and those who were not affected by the flood. (2) Poorer households lost less than their richer neighbors in absolute terms, but more when compared with their annual expenditure level, and poorer households are over-represented among the most severely affected households. (3) More than 30 percent of the affected households report not having recovered two years after the shock, and the ability of households to recover was driven by the magnitude of their losses, sources of income, and access to coping mechanisms, but not by their poverty, as measured by the annual expenditure level. (4) There is a measurable effect of the flood on behaviors, under-mining savings and investment in enterprises. The study concludes with two policy implications. First, flood management could be considered as a component of the poverty-reduction strategy in the city. Second, building resilience is not only about increasing income. It also requires providing the population with coping and recovery mechanisms such as financial instruments. A flood management program needs to be designed to target low-resilience households, such as those with little access to coping and recovery mechanisms, even those who are not living in poverty before the shock. -
Publication
Resilient Infrastructure for Thriving Firms: A Review of The Evidence
(World Bank, Washington, DC, 2019-06)This review examines the literature on the role of infrastructure in determining the productivity and competitiveness of firms. It shows that the existing evidence base is clear in concluding that reliable and high-quality infrastructure is a crucial foundation for enabling businesses to thrive. It demonstrates that the provision of electricity, transport, water, and telecommunications systems increases firm-level productivity. It also shows that providing infrastructure per se is not enough to boost productivity, unless it offers reliable service. Disruptions and irregular service have substantial adverse effects on firms, not least due to disrupted supply chains, underutilization of production capacity, and costly adaptation measures. -
Publication
How Inertia and Limited Potentials Affect the Timing of Sectoral Abatements in Optimal Climate Policy
(World Bank, Washington, DC, 2012-08)This paper investigates the optimal timing of greenhouse gas abatement efforts in a multi-sectoral model with economic inertia, each sector having a limited abatement potential. It defines economic inertia as the conjunction of technical inertia -- a social planner chooses investment on persistent abating activities, as opposed to choosing abatement at each time period independently -- and increasing marginal investment costs in abating activities. It shows that in the presence of economic inertia, optimal abatement efforts (in dollars per ton) are bell-shaped and trigger a transition toward a low-carbon economy. The authors prove that optimal marginal abatement costs should differ across sectors: they depend on the global carbon price, but also on sector-specific shadow costs of the sectoral abatement potential. The paper discusses the impact of the convexity of abatement investment costs: more rigid sectors are represented with more convex cost functions and should invest more in early abatement. The conclusion is that overlapping mitigation policies should not be discarded based on the argument that they set different marginal costs (`"different carbon prices"') in different sectors. -
Publication
Designing Climate Change Adaptation Policies : An Economic Framework
( 2011-02-01)Adaptation has long been neglected in the debate and policies surrounding climate change. However, increasing awareness of climate change has led many stakeholders to look for the best way to limit its consequences and has resulted in a large number of initiatives related to adaptation, particularly at the local level. This report proposes a general economic framework to help stakeholders in the public sector to develop effective adaptation strategies. To do so, it lays out the general issues involved in adaptation, including the role of uncertainty and inertia, and the need to consider structural changes in addition to marginal adjustments. Then, it identifies the reasons for legitimate public action in terms of adaptation, and four main domains of action: the production and dissemination of information on climate change and its impacts; the adaptation of standards, regulations and fiscal policies; the required changes in institutions; and direct adaptation actions of governments and local communities in terms of public infrastructure, public buildings and ecosystems. Finally, the report suggests a method to build public adaptation plans and to assess the desirability of possible policies. -
Publication
Socioeconomic Resilience in Sri Lanka: Natural Disaster Poverty and Wellbeing Impact Assessment
(World Bank, Washington, DC, 2019-09)Traditional 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 the main measure of disaster severity. Using an 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 Sri Lanka. The analysis indicates that regular flooding events can move tens of thousands of Sri Lankans into transient poverty at once, hindering the country's recent progress on poverty eradication and shared prosperity. As metrics of disaster impacts, poverty incidence and well-being losses facilitate quantification of the benefits of interventions like rapid post-disaster support and adaptive social protection systems. Such investments efficiently reduce wellbeing losses by making exposed and vulnerable populations more resilient. Nationally and on average, the bottom income quintile suffers only 7 percent of the total asset losses but 32 percent of the total wellbeing losses. Average annual wellbeing losses due to fluvial flooding in Sri Lanka are estimated at US$119 million per year, more than double the asset losses of US$78 million. Asset losses are reported to be highly concentrated in Colombo district, and wellbeing losses are more widely distributed throughout the country. Finally, the paper applies the socioeconomic resilience framework to a cost-benefit analysis of prospective adaptive social protection systems, based on enrollment in Samurdhi, the main social support system in Sri Lanka. -
Publication
Strengthening New Infrastructure Assets: A Cost-Benefit Analysis
(World Bank, Washington, DC, 2019-06)This paper explores the benefits and the costs of strengthening infrastructure assets to make them more resilient, reducing the repair costs and infrastructure disruptions caused by natural hazards. Strengthening infrastructure assets in low- and middle-income countries would increase investment needs in power, transport, and water and sanitation by between $11 billion and $65 billion a year, i.e. 3 percent of baseline infrastructure investment needs. The uncertainty pertaining to the costs and benefits of infrastructure resilience makes it difficult to provide a single estimate for the benefit-cost ratio of strengthening exposed infrastructure assets. To manage this uncertainty, this paper explores the benefit-cost ratio in 3,000 scenarios, combining uncertainties in all parameters of the analysis. The benefit-cost ratio is higher than 1 in 96 percent of the scenarios, larger than 2 in 77 percent of them, and higher than 4 in half of them. The net present value of these investments over the lifetime of new infrastructure assets -- or, equivalently, the cost of inaction -- exceeds $2 trillion in 75 percent of the scenarios and $4.2 trillion in half of them. Moreover, climate change makes the strengthening of infrastructure assets even more important, doubling the median benefit-cost ratio. -
Publication
A Dynamic Model of Extreme Risk Coverage : Resilience and Efficiency in the Global Reinsurance Market
( 2011-09-01)This paper presents a dynamic model of the reinsurance market for catastrophe risks. The model is based on the classical capacity-constraint assumption. Reinsurers choose every year the quantity of risk they cover and the level of external capital they raise to cover these risks. The model exhibits time dependency and reproduces a market dynamics that shares many features with the real market. In particular, market price increases and reinsurance coverage decreases after large shocks, and a series of smaller losses may have a deeper impact than one larger loss. There is a significant oligopoly effect reducing reinsurance supply, and the market is segregated into strategic large actors that influence market prices and price-taker smaller firms. A regulation trade-off between market efficiency and resilience is identified and quantified: improving the ability of the market to cope with exceptional events increases the cost of reinsurance. This model provides an interesting basis to analyze further capacity needs for the insurance industry in view of growing worldwide exposure to catastrophic risks and climate change. -
Publication
The Economics of Natural Disasters : Concepts and Methods
( 2010-12-01)Large-scale disasters regularly affect societies over the globe, causing large destruction and damage. After each of these events, media, insurance companies, and international institu-tions publish numerous assessments of the "cost of the disaster." However these assessments are based on different methodologies and approaches, and they often reach different results. Besides methodological differences, these discrepancies are due to the multi-dimensionality in disaster impacts and their large redistributive effects, which make it unclear what is included in the estimates. But most importantly, the purpose of these assessments is rarely specified, although different purposes correspond to different perimeters of analysis and different definitions of what a cost is. To clarify this situation, this paper proposes a definition of the cost of a disaster, and emphasizes the most important mechanisms that explain and determine this cost. It does so by first explaining why the direct economic cost, that is, the value of what has been damaged or destroyed by the disaster, is not a sufficient indicator of disaster seriousness and why estimating indirect losses is crucial to assess the consequences on welfare. The paper describes the main indirect consequences of a disaster and the following reconstruction phase, and discusses the economic mechanisms at play. It proposes a review of available methodologies to assess indirect economic consequences, illustrated with examples from the literature. Finally, it highlights the need for a better understanding of the economics of natural disasters and suggests a few promising areas for research on this topic. -
Publication
When Starting with the Most Expensive Option Makes Sense : Use and Misuse of Marginal Abatement Cost Curves
( 2011-09-01)This article investigates the use of expert-based Marginal Abatement Cost Curves (MACC) to design abatement strategies. It shows that introducing inertia, in the form of the "cost in time" of available options, changes significantly the message from MACCs. With an abatement objective in cumulative emissions (e.g., emitting less than 200 GtCO2 in the 2000-2050 period), it makes sense to implement some of the more expensive options before the potential of the cheapest ones has been exhausted. With abatement targets expressed in terms of emissions at one point in time (e.g., reducing emissions by 20 percent in 2020), it can even be preferable to start with the implementation of the most expensive options if their potential is high and their inertia significant. Also, the best strategy to reach a short-term target is different depending on whether this target is the ultimate objective or there is a longer-term target. The best way to achieve Europe's goal of 20 percent reduction in emissions by 2020 is different if this objective is the ultimate objective or if it is only a milestone in a trajectory toward a 75 percent reduction in 2050. The cheapest options may be sufficient to reach the 2020 target but could create a carbon-intensive lock-in and preclude deeper emission reductions by 2050. These results show that in a world without perfect foresight and perfect credibility of the long-term carbon-price signal, a unique carbon price in all sectors is not the most efficient approach. Sectoral objectives, such as Europe's 20 percent renewable energy target in Europe, fuel-economy standards in the auto industry, or changes in urban planning, building norms and infrastructure design are a critical part of an efficient mitigation policy.