About the GDL Vulnerability Index
The GDL Vulnerability Index (GVI) is a composite index designed to monitor and project socio-economic vulnerability to climate change.
The GVI is a flexible and easy to use index, developed for use by experts as well as non-experts in the climate field, including researchers, (local) politicians, NGO’s, journalists, advocacy groups and grassroot movements.
Composite indices, such as the GVI, summarize the different aspects of vulnerability in a single number. This makes them very useful for comparing countries and studying trends.
The GVI is based on an additive formula in which indicators measuring seven major socio-economic dimensions of vulnerability are combined, i.e. economy, education, health, the position of women, governance, demography and infrastructure. Any area of the world can be ranked on the GVI scale by filling in the underlying indicator values in a simple formula.
The same formula can be used to compute the vulnerability of a country, grouping of countries (e.g. East Africa, South Asia, the Arabic world) or subnational region (province, district), as long as the required information is available. GVI scores are therefore highly comparable and independent of the kind of area or point in time for which they are computed.
To construct the GVI, Principal Component Aanalysis was applied to a database with data derived from the World Bank and the UNDP for 155 countries in the period 2015-2020. The first component, explaining 67% of the variation in the data, was chosen as the central index.
The component scores were rescaled into an additive formula ranging from 0 to 100, with a value of 100 indicating very high vulnerability and a value of 0 very little vulnerability.
The formula approach makes it possible to construct projections of the GVI for 2020-2100 along the Shared Socio-economic Pathways (SSPs) by using estimates of future values of the underlying indicators.