Indices of Social Vulnerability to Natural Hazards: A Comparative Evaluation
Advisor: Dr. Susan L. Cutter
In recent years, numerous approaches to measure social vulnerability at the global scale have emerged. However, little is known about the accuracy and validity of these social vulnerability indices. This dissertation evaluates selected indices of social vulnerability (Prevalent Vulnerability Index, Disaster Risk Index, Predictive Indicators of Vulnerability, and Index of Social Vulnerability to Climate Change for Africa) along with the Human Development Index, the Human Well-being Index and parts of the Environmental Sustainability Index. The goal is to establish a framework for index evaluation that allows for the identification of methodologically robust approaches and the assessment of the overall quality of each index. The following questions guide this research:
- What are the methodological differences between selected indices of social vulnerability?
- Are these indices internally sound and robust?
- Do these indices withstand external validation through proxy measures?
- Is there geographic variability in the mapped results of the indices?
To answer these questions a mixture of critical qualitative analysis, sensitivity analyses, comparisons with potential proxy measures of social vulnerability, and spatial statistics is employed. The results reveal significant shortcomings in the construction of most of the evaluated indices with particular gaps in empirical validity and methodological robustness. The Index of Predictive Indicators of Vulnerability mimics development-oriented indices such as the Human Development Index rather than social vulnerability. The Disaster Risk Index exhibits ecological fallacy problems, which strongly challenges its validity. The Index of Social Vulnerability to Climate Change for Africa shows little thematic specificity in its indicator selection and uses arbitrary weights. The Prevalent Vulnerability Index for Latin America employs vulnerability-relevant indicators but suffers from methodological weaknesses when it comes to indicator aggregation and weighting. Four key issues contribute to variability and uncertainty embodied by current vulnerability indices: subjective interpretation of vulnerability concepts, ignorance of sound statistical practices, limited data availability, and absence of reliable approaches to calibrate social vulnerability indices. To overcome these deficits, the research community will need to advance conceptual frameworks, develop (social) vulnerability-relevant data sets, focus on evidencing index construction empirically, and pursue the validation of indices through proxy measures or other means.Dissertation