Publication: Investment Decision Making Under Deep Uncertainty : Application to Climate Change
Loading...
Date
2012-09
ISSN
Published
2012-09
Author(s)
Editor(s)
Abstract
While agreeing on the choice of an optimal investment decision is already difficult for any diverse group of actors, priorities, and world views, the presence of deep uncertainties further challenges the decision-making framework by questioning the robustness of all purportedly optimal solutions. This paper summarizes the additional uncertainty that is created by climate change, and reviews the tools that are available to project climate change (including downscaling techniques) and to assess and quantify the corresponding uncertainty. Assuming that climate change and other deep uncertainties cannot be eliminated over the short term (and probably even over the longer term), it then summarizes existing decision-making methodologies that are able to deal with climate-related uncertainty, namely cost-benefit analysis under uncertainty, cost-benefit analysis with real options, robust decision making, and climate informed decision analysis. It also provides examples of applications of these methodologies, highlighting their pros and cons and their domain of applicability. The paper concludes that it is impossible to define the "best" solution or to prescribe any particular methodology in general. Instead, a menu of methodologies is required, together with some indications on which strategies are most appropriate in which contexts. This analysis is based on a set of interviews with decision-makers, in particular World Bank project leaders, and on a literature review on decision-making under uncertainty. It aims at helping decision-makers identify which method is more appropriate in a given context, as a function of the project's lifetime, cost, and vulnerability.
Link to Data Set
Citation
“Shah, Ankur; Hallegatte, Stéphane; Lempert, Robert; Brown, Casey; Gill, Stuart. 2012. Investment Decision Making Under Deep Uncertainty : Application to Climate Change. Policy Research Working Paper; No. 6193. © World Bank. http://hdl.handle.net/10986/12028 License: CC BY 3.0 IGO.”
Associated URLs
Associated content
Other publications in this report series
Publication The Future of Poverty(Washington, DC: World Bank, 2025-07-15)Climate change is increasingly acknowledged as a critical issue with far-reaching socioeconomic implications that extend well beyond environmental concerns. Among the most pressing challenges is its impact on global poverty. This paper projects the potential impacts of unmitigated climate change on global poverty rates between 2023 and 2050. Building on a study that provided a detailed analysis of how temperature changes affect economic productivity, this paper integrates those findings with binned data from 217 countries, sourced from the World Bank’s Poverty and Inequality Platform. By simulating poverty rates and the number of poor under two climate change scenarios, the paper uncovers some alarming trends. One of the primary findings is that the number of people living in extreme poverty worldwide could be nearly doubled due to climate change. In all scenarios, Sub-Saharan Africa is projected to bear the brunt, contributing the largest number of poor people, with estimates ranging between 40.5 million and 73.5 million by 2050. Another significant finding is the disproportionate impact of inequality on poverty. Even small increases in inequality can lead to substantial rises in poverty levels. For instance, if every country’s Gini coefficient increases by just 1 percent between 2022 and 2050, an additional 8.8 million people could be pushed below the international poverty line by 2050. In a more extreme scenario, where every country’s Gini coefficient increases by 10 percent between 2022 and 2050, the number of people falling into poverty could rise by an additional 148.8 million relative to the baseline scenario. These findings underscore the urgent need for comprehensive climate policies that not only mitigate environmental impacts but also address socioeconomic vulnerabilities.Publication Exports, Labor Markets, and the Environment(Washington, DC: World Bank, 2025-07-14)What is the environmental impact of exports? Focusing on 2000–20, this paper combines customs, administrative, and census microdata to estimate employment elasticities with respect to exports. The findings show that municipalities that faced increased exports experienced faster growth in formal employment. The elasticities were 0.25 on impact, peaked at 0.4, and remained positive and significant even 10 years after the shock, pointing to a long and protracted labor market adjustment. In the long run, informal employment responds negatively to export shocks. Using a granular taxonomy for economic activities based on their environmental impact, the paper documents that environmentally risky activities have a larger share of employment than environmentally sustainable ones, and that the relationship between these activities and exports is nuanced. Over the short run, environmentally risky employment responds more strongly to exports relative to environmentally sustainable employment. However, over the long run, this pattern reverses, as the impact of exports on environmentally sustainable employment is more persistent.Publication The Macroeconomic Implications of Climate Change Impacts and Adaptation Options(Washington, DC: World Bank, 2025-05-29)Estimating the macroeconomic implications of climate change impacts and adaptation options is a topic of intense research. This paper presents a framework in the World Bank's macrostructural model to assess climate-related damages. This approach has been used in many Country Climate and Development Reports, a World Bank diagnostic that identifies priorities to ensure continued development in spite of climate change and climate policy objectives. The methodology captures a set of impact channels through which climate change affects the economy by (1) connecting a set of biophysical models to the macroeconomic model and (2) exploring a set of development and climate scenarios. The paper summarizes the results for five countries, highlighting the sources and magnitudes of their vulnerability --- with estimated gross domestic product losses in 2050 exceeding 10 percent of gross domestic product in some countries and scenarios, although only a small set of impact channels is included. The paper also presents estimates of the macroeconomic gains from sector-level adaptation interventions, considering their upfront costs and avoided climate impacts and finding significant net gross domestic product gains from adaptation opportunities identified in the Country Climate and Development Reports. Finally, the paper discusses the limits of current modeling approaches, and their complementarity with empirical approaches based on historical data series. The integrated modeling approach proposed in this paper can inform policymakers as they make proactive decisions on climate change adaptation and resilience.Publication The Asymmetric Bank Distress Amplifier of Recessions(Washington, DC: World Bank, 2025-07-11)One defining feature of financial crises, evident in U.S. and international data, is asymmetric bank distress—concentrated losses on a subset of banks. This paper proposes a model in which shocks to borrowers’ productivity dispersion lead to asymmetric bank losses. The framework exhibits a “bank distress amplifier,” exacerbating economic downturns by causing costly bank failures and raising uncertainty about the solvency of banks, thereby pushing banks to deleverage. Quantitative analysis shows that the bank distress amplifier doubles investment decline and increases the spread by 2.5 times during the Great Recession compared to a standard financial accelerator model. The mechanism helps explain how a seemingly small shock can sometimes trigger a large crisis.Publication Impact of Heat Waves on Learning Outcomes and the Role of Conditional Cash Transfers(Washington, DC: World Bank, 2025-07-14)This paper evaluates the impact of higher temperatures on learning outcomes in Peru. The results suggest that 1 degree above 20°C is equivalent to 7 and 6 percent of a standard deviation of what a student learns in a year for math and reading tests, respectively. These results hold true when the main specification is changed, splitting the sample, collapsing the data at school level, and using other climate specifications. The paper aims to improve understanding of how to deal with the impacts of climate change on learning outcomes in developing countries. The evidence suggests that conditional cash transfer programs can mitigate the negative effects of higher temperatures on students’ learning outcomes in math and reading.
Journal
Journal Volume
Journal Issue
Collections
Related items
Showing items related by metadata.
Publication Agreeing on Robust Decisions : New Processes for Decision Making under Deep Uncertainty(World Bank, Washington, DC, 2014-06)Investment decision making is already difficult for any diverse group of actors with different priorities and views. But the presence of deep uncertainties linked to climate change and other future conditions further challenges decision making by questioning the robustness of all purportedly optimal solutions. While decision makers can continue to use the decision metrics they have used in the past (such as net present value), alternative methodologies can improve decision processes, especially those that lead with analysis and end in agreement on decisions. Such "Agree-on-Decision" methods start by stress-testing options under a wide range of plausible conditions, without requiring us to agree ex ante on which conditions are more or less likely, and against a set of objectives or success metrics, without requiring us to agree ex ante on how to aggregate or weight them. As a result, these methods are easier to apply to contexts of large uncertainty or disagreement on values and objectives. This inverted process promotes consensus around better decisions and can help in managing uncertainty. Analyses performed in this way let decision makers make the decision and inform them on (1) the conditions under which an option or project is vulnerable; (2) the tradeoffs between robustness and cost, or between various objectives; and (3) the flexibility of various options to respond to changes in the future. In doing so, they put decision makers back in the driver's seat. A growing set of case studies shows that these methods can be applied in real-world contexts and do not need to be more costly or complicated than traditional approaches. Finally, while this paper focuses on climate change, a better treatment of uncertainties and disagreement would in general improve decision making and development outcomes.Publication Economics of Adaptation to Climate Change : Samoa(Washington, DC, 2010)Over the last two decades Samoa has suffered major damage from two cyclones in 1990-91, minor damage from a third cyclone in 2004, and an earthquake tsunami in 2009. Changes in the scale and impact of these types of natural disasters are likely to be important consequences of climate change for the country because the increases in sea level and in average sea surface temperatures will increase theintensity and damage from major storms. Other potential impacts are linked to changes in the weather patterns associated with El Niño Southern Oscillation (ENSO) events. The primary concern focuses on the impact on agriculture, especially in periods of lower precipitation following strong El Niño episodes.This study examines the consequences of an increase in average temperatures of up to 1°C by 2050 and up to 2.75°C by 2100 for the frequency and intensity of major cyclones that hit the islands. Estimates of the economic damage caused by storms in the past have been used to calibrate a damage function that yields an estimated increase in the expected value of economic damage as the peak wind speeds for storms with return periods of 10, 50, or 100 years rise over time. In this framework the key element of adaptation is to ensure that buildings and other assets are designed to standards that enable them to cope with the greater wind stresses and more intense precipitation associated with worse storms.Publication Climate Risk and Financial Institutions(International Finance Corporation, Washington, D.C., 2011)This report analyzes in some detail the risks to project finance and the performance of real-sector investments. Options, futures, derivatives, foreign exchange and more exotic instruments are not specifically addressed. The objectives of institutional investors, such as pension funds, include creation of sustained revenues over a long period of time. Clearly, given this long-term perspective, institutional investors need to be particularly aware of growing risks to their investments in climatically sensitive sectors or regions. This report demonstrates that climate change and its impacts are likely to alter a number of conditions that are material to the objectives of financial institutions. If changing conditions are not actively managed, investments and institutions may underperform. Most investments will be channeled through financial institutions. Given that the main effects of climate change are now well established, there is a considerable opportunity, as well as a responsibility, for these institutions to take a leading role in adaptation to climate change. Institutions managing investments in long-lived assets have both a direct financial risk to consider and the opportunity to create value by working proactively with their clients and other stakeholders to take steps to manage the risks. Going forward, International Finance Corporation (IFC) will initiate the development of more general tools addressing climate risks and investments.Publication Beyond Downscaling : A Bottom-Up Approach to Climate Adaptation for Water Resources Management(World Bank Group, Washington, DC, 2014-09-11)This report focuses on how we achieve water sustainability over long timescales - decades, even centuries from now. These timescales are important and relevant to our decisions about planning, infrastructure, and institutions today. Many of the methods we use to manage water, directly or indirectly, commit us to future decision pathways and restrict us from making other, alternative decisions. Across the first four chapters, this report describes the challenges of including climate change in water management decision-making and provides an overview of current practices in the adaptation field. After considering the pros and cons of these practices, the book concludes with a framework for an adaptation approach supported by Alliance for Global Water Adaptation (AGWA).Publication Assessing the Potential Consequences of Climate Destabilization in Latin America(World Bank, Washington, DC, 2009-01)Estimating the potential costs of climate destabilization is not a trivial matter. Potential climate impacts have multiple consequences, some of which can be monetized while others are beyond the reach of standard economic tools. A full assessment of the implications of climate impacts often cannot be completed because many of the consequences are only partly known. This report summarizes data recently made available, through the portfolio of adaptation activities in the region, on some of the damages induced by climate destabilization. These include impacts from hurricane intensification, glacier retreat, and increased exposure to tropical vector diseases, coral bleaching, and composite costs of climate change in the particularly vulnerable Caribbean Basin. Other costs are becoming evident but they still cannot be estimated. Most worrisome among these are the potential implications from Amazon dieback which, if realized, will drastically affect the water cycle in the region as well as environmental services essential to economic activity in the region, with wider global implications. The report refers to destabilization in the title as recognition, that the region is now facing impacts from major, destabilizing changes in its climate.
Users also downloaded
Showing related downloaded files
Publication Government Matters III : Governance Indicators for 1996-2002(World Bank, Washington, DC, 2003-08)The authors present estimates of six dimensions of governance covering 199 countries and territories for four time periods: 1996, 1998, 2000, and 2002. These indicators are based on several hundred individual variables measuring perceptions of governance, drawn from 25 separate data sources constructed by 18 different organizations. The authors assign these individual measures of governance to categories capturing key dimensions of governance and use an unobserved components model to construct six aggregate governance indicators in each of the four periods. They present the point estimates of the dimensions of governance as well as the margins of errors for each country for the four periods. The governance indicators reported here are an update and expansion of previous research work on indicators initiated in 1998 (Kaufmann, Kraay, and Zoido-Lobat 1999a,b and 2002). The authors also address various methodological issues, including the interpretation and use of the data given the estimated margins of errors.Publication Governance Matters VIII : Aggregate and Individual Governance Indicators 1996–2008(2009-06-01)This paper reports on the 2009 update of the Worldwide Governance Indicators (WGI) research project, covering 212 countries and territories and measuring six dimensions of governance between 1996 and 2008: Voice and Accountability, Political Stability and Absence of Violence/Terrorism, Government Effectiveness, Regulatory Quality, Rule of Law, and Control of Corruption. These aggregate indicators are based on hundreds of specific and disaggregated individual variables measuring various dimensions of governance, taken from 35 data sources provided by 33 different organizations. The data reflect the views on governance of public sector, private sector and NGO experts, as well as thousands of citizen and firm survey respondents worldwide. The authors also explicitly report the margins of error accompanying each country estimate. These reflect the inherent difficulties in measuring governance using any kind of data. They find that even after taking margins of error into account, the WGI permit meaningful cross-country comparisons as well as monitoring progress over time. The aggregate indicators, together with the disaggregated underlying indicators, are available at www.govindicators.org.Publication Governance Matters IV : Governance Indicators for 1996-2004(World Bank, Washington, DC, 2005-06)The authors present the latest update of their aggregate governance indicators, together with new analysis of several issues related to the use of these measures. The governance indicators measure the following six dimensions of governance: (1) voice and accountability; (2) political instability and violence; (3) government effectiveness; (4) regulatory quality; (5) rule of law, and (6) control of corruption. They cover 209 countries and territories for 1996, 1998, 2000, 2002, and 2004. They are based on several hundred individual variables measuring perceptions of governance, drawn from 37 separate data sources constructed by 31 organizations. The authors present estimates of the six dimensions of governance for each period, as well as margins of error capturing the range of likely values for each country. These margins of error are not unique to perceptions-based measures of governance, but are an important feature of all efforts to measure governance, including objective indicators. In fact, the authors give examples of how individual objective measures provide an incomplete picture of even the quite particular dimensions of governance that they are intended to measure. The authors also analyze in detail changes over time in their estimates of governance; provide a framework for assessing the statistical significance of changes in governance; and suggest a simple rule of thumb for identifying statistically significant changes in country governance over time. The ability to identify significant changes in governance over time is much higher for aggregate indicators than for any individual indicator. While the authors find that the quality of governance in a number of countries has changed significantly (in both directions), they also provide evidence suggesting that there are no trends, for better or worse, in global averages of governance. Finally, they interpret the strong observed correlation between income and governance, and argue against recent efforts to apply a discount to governance performance in low-income countries.Publication Breaking the Conflict Trap : Civil War and Development Policy(Washington, DC: World Bank and Oxford University Press, 2003)Most wars are now civil wars. Even though international wars attract enormous global attention, they have become infrequent and brief. Civil wars usually attract less attention, but they have become increasingly common and typically go on for years. This report argues that civil war is now an important issue for development. War retards development, but conversely, development retards war. This double causation gives rise to virtuous and vicious circles. Where development succeeds, countries become progressively safer from violent conflict, making subsequent development easier. Where development fails, countries are at high risk of becoming caught in a conflict trap in which war wrecks the economy and increases the risk of further war. The global incidence of civil war is high because the international community has done little to avert it. Inertia is rooted in two beliefs: that we can safely 'let them fight it out among themselves' and that 'nothing can be done' because civil war is driven by ancestral ethnic and religious hatreds. The purpose of this report is to challenge these beliefs.Publication Design Thinking for Social Innovation(2010-07)Designers have traditionally focused on enchancing the look and functionality of products.