Measuring insularity as a state of nature

In this paper we construct a composite index that measures insularity for countries that are islands and for those that have islands. By collecting available physical data for all islands in the world, be they states or regions, we provide a novel data set of insularity along different dimensions. Three of these contribute to making insularity more or less severe: the degree of land dispersion, the remoteness and the average size of the island. We aggregate this information, weighting it by the share of insular land at the country level, and compute a measure of insularity that ranges between 0 and 100. We find that the greater burden linked to insularity is borne by islands with no territorial sovereignty.