A country is given a score for each pillar. This score is based on that country’s performance with respect to each of the indicators in that pillar, and the level of that indicator’s importance (the weight assigned to each indicator), which is discussed in the Methodology Report. Finally, the pillar scores are averaged to obtain an overall prosperity score, which determines each country’s rank. Each pillar contains around 12 indicators. We have also aggregated the indicators into sub-pillars, to capture an intermediate perspective. While the Index score provides an overall assessment of a country’s prosperity, each pillar (and sub-pillar) score serves as a reliable guide to how that country is performing with respect to a particular foundation of prosperity.
We continuously monitor the quality and availability of global data, which is not constant. As a result of datasets being discontinued, or new datasets becoming available, we have updated some of the variables used in the Index. For example:
Under the Health pillar, the World Bank replaced the variable called “Improved sanitation facilities”, with two new variables: “People using at least basic sanitation services (% of population)”, and “People using safely managed sanitation services (% of population)”. We chose the first of these measures, because it had greater coverage and a higher correlation with the old measure.
In the Natural Environment pillar, the air pollution measure has changed. In the latest data release, the Environmental Performance Index, has used a weighted average of four levels of air pollution, unlike previous years when it had used a different weighting system. We have used their new measure in this year’s Prosperity Index.
In the Economic Quality pillar, the International Monetary Fund (IMF) had not updated the Export Diversification Index since 2010. We therefore chose to replace the IMF measure with the Harvard Economic Complexity Index, which is a measure of export diversity.
In all cases, we updated the historical data. This resulted in some minor changes to scores and rankings for prior years; the overall effect, however, is small. A full list of changes and updates to variables can be found in the
2018 Methodology Report.