Social vulnerability and poor outcomes in a disaster – a test of measures and models

Generally speaking, social vulnerability has long been associated with poor outcomes in post-disaster settings. Individuals and groups with the least access to economic and material resources, and the least engagement with civic institutions of political and communal power, are often more likely to be situated in harm's way before a disaster strikes, and are also far less prepared to adapt and cope with its consequences in the wake of a disaster. Several commonly-used social vulnerability indices, including Cutter's Social Vulnerability Index and the UNDP's Human Development Index, were tested for their predictive quality, using census and economic data for Louisiana and Mississippi. County-level data predating Hurricane Katrina were used to establish social vulnerability measures, and they were examined for their association with economic and health-related outcomes in affected and non-affected counties, post-Katrina. Counties were distinguished by whether or not they were designated by FEMA as having sustained considerable damage (117 counties, operating as “cases”) and those counties less affected by the storm (“controls”). Establishing valid and reliable measures of population vulnerability can assist public health and emergency planners in mitigating, preventing, and preparing for disasters, particularly for the most vulnerable populations.