Estimates of trends in global income and resource inequalities

It is often argued that the inequality in the world is increasing. We study the global income and resource inequality between 1960 and late 1990s. Income is measured in GDP/capita in terms of both current market exchange rate and purchasing power parity (PPP). Consumption of paper, energy, electricity, food, animal food, as well as emissions of carbon dioxide, is also studied. Changes in the absolute and relative gap between the top and bottom 20% consumers as well as the Atkinson measure are used as inequality indicators. Some remarks are made on how to compare income across countries and how inequality should be measured. We find that the inequality in terms of GDP/capita measured in PPP terms is rather stable in relative terms, but increasing in absolute terms. We conclude that inequality as measured by the Atkinson index is decreasing for all resources but that the gap in resource consumption in absolute terms is increasing for paper and electricity consumption.