Rising levels of inequality has become a key political issue in recent years; “the defining issue of our time,” as Barack Obama described it back in 2013. It was at the heart of the Occupy movement protests, and has received a huge amount of attention in the media and in policy circles. But much of this discussion has focussed on what’s been happening in rich countries, in particular upon trends seen in the US. We tend to hear less about inequality in the rest of the world.
How has income inequality within countries been changing around the world more generally?
To answer this question, we brought together estimates of income inequality for two points in time: today and a generation ago in 1990. Our metric of income inequality is the Gini index – explained here– which is higher in a country with higher inequality.1
We rely on estimates from two online databases: PovcalNet, run by the World Bank, and the Chartbook of Economic Inequality, which I published together with Tony Atkinson, Salvatore Morelli, and Max Roser.2 This gave us a sample of 83 countries, covering around 85% of the world’s population (download the data here).
The chart below compares levels of inequality today with those one generation ago. If you’ve not seen this sort of chart before, it may take a moment to understand what’s going on. How high a country is in the chart shows you the level of inequality in 2015. How far to the right shows you the level of inequality in 1990.3 In addition, a 45 degree line is plotted. Countries below this line saw a fall in the Gini index between the two dates; countries above saw an increase.