The hazards of indicators: Insights from the environmental vulnerability index

Since the early 1990s a number of projects have developed indexes to measure vulnerability to environmental change. This article investigates the key conceptual and methodological problems associated with such indexes. It examines in detail an index that explicitly addresses environmental change as an issue of vulnerability, the Environmental Vulnerability Index (EVI) developed by the South Pacific Applied Geoscience Commission (SOPAC). This examination offers some broader lessons for indicator-based projects, all of which require a simple model of complex and uncertain social-ecological systems, and entail difficult choices about the selection, standardization, weighting, and aggregation of indicators selected to represent important aspects of those systems. We conclude that indexes of vulnerability to environmental change cannot hope to be meaningful when applied to large-scale systems, and so should focus on smaller scales of analysis. We argue that they should not be used as the basis for disbursing funds, comparing countries, or for measuring the performance of countries in environmental management. We also argue that vulnerability is a context-specific rather than a generic condition. Finally, we suggest that because vulnerability is about values at risk, there should be more input from a broader array of people when indexes are being developed and tested.