Understanding vulnerability matters because being vulnerable represents a profoundly undesirable state. People who experience vulnerability in old age are of obvious humanitarian concern, as their insecurity and heightened exposure to certain threats is likely to be compounded by reduced capacities for coping independently. Comprehension of the causes and consequences of vulnerability is important for the development of social policies as it indicates ways of avoiding and alleviating bad outcomes. Policies which have the concept of vulnerability at their heart encourage the development of preventive and targeted measures, which is crucial in conditions of financial constraints and competing demands. By studying vulnerability we investigate processes of relative disadvantage or exclusion and, for purposes of comparison, absolute differences in socio-economic or policy context can be set aside. This makes the study of vulnerability particularly germane to cross-cultural and cross-national research on old-age and elderly support.