How to measure vulnerability and resilience? Lessons learnt from the pioneer studies on small islands developing states (SIDS)

Small islands developing states constitute a fruitful topic to work on concerning the question of vulnerability and resilience. As debated in the economic literature, these territories present structural characteristics - smallness, remoteness and insularity - that are considered as strong handicaps, which impede their development. Several empirical tests have been implemented to measure the vulnerability of SIDS. The results reveal the importance of the phenomenon but are resolutely based on different computation methods and do not systematically cope with sustainable considerations. Therefore, there are as many methodologies as empirical studies, a fact that can seriously be prejudicial not only to the robustness of the results, but also to the validity of the used methodologies which appear contingent to the specific studied resilience. It is based on the graph theory and the Nepomiastchy-Ravelli algorithm in order identify a minimum set of variables respecting five dimensions that should necessarily be taken into account: economic, social, environment, governance, insularity. A complete and new composite index of vulnerability and resilience is suggested in accordance with the following generic principles: accuracy, simplicity, ease of interpretation, computation robustness, comparability, universality and flexibility.