The study used a method called Theil’s second measure to look at differences in how much water is available per person in different countries. They found that inequalities in water availability have decreased over time, with differences both within and between groups of countries. Currently, the biggest gap in water availability is between different groups of countries. The study also showed that countries in the Middle East are contributing to an increase in inequalities, while countries in North America, Asia, and Oceania are helping to reduce these inequalities.