The Changing Shape of Global Inequality - exploring a new dataset

A new dataset for estimating the development of global inequality between 1820 and 2000 is presented, based on a large variety of sources and methods for estimating (gross household) income inequality. On this basis, and two sets of benchmarks for estimating between-country inequality (the Maddison 1990 benchmark and the recent 2005 ICP round), we estimate the evolution of global income inequality and of the number of people below various poverty lines over the past two centuries. We find that between 1820 and 1950 increasing per capita income is combined with increasing global inequality, and with an increase in the absolute number of people below the poverty line. After 1950 global inequality as measured by the Gini coefficient remains more or less constant, and also the number of poor starts to decline in absolute terms. It also appears that the global income distribution was uni-modal in the 19th century, became increasingly bi-modal between 1910 and 1970 with two world wars, a depression and de-globalization, and was suddenly transformed back into a uni-modal distribution between 1980 and 2000.