Indirect Costs of Natural Hazards

Large-scale disasters regularly affect societies over the globe, causing large destruction and damage. After each of these events, media, insurance companies, and international institutions 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.

This report is part of the EU project ConHaz. The first objective of ConHaz is to compile state-of-the-art methods and terminology as used in European case studies. This compilation will consider droughts, floods, storms, and alpine hazards, as well as various impacted sectors, such as agriculture, health and nature. It will consider direct, indirect and intangible costs. ConHaz further examines the costs and benefits of risk-prevention and emergency response policies. The second objective of ConHaz is to evaluate the compiled methods by considering theoretical assumptions underlying cost assessment methods and issues appearing in application of the methods, such as availability and quality of data. ConHaz will also assess the reliability of the end results by considering the accuracy of cost predictions and best-practice methods of validation, and will identify relevant gaps in assessment methods. The third objective of ConHaz is to compare available assessment methods with end-user needs and practices, so as to better identify best practice and knowledge gaps in relation to policy-making. A final objective of ConHaz is to give recommendations about best practices and to identify resulting research needs.