Inequality and development across and within countries

SummaryThis paper provides a cross-country comparison of how income inequality has evolved within countries at different levels of development. It uses overlapping nonparametric regression, which allows visual comparisons of inequality both within and across countries. As a result, the methodology allows more specific conclusions than cross-country regressions, and yet is more general than within-country case studies. The approach highlights the problematic conclusions that can arise with parametric regressions, in particular with tests of the Kuznets curve. While some previous results are confirmed, some new results on inequality across countries are also discovered.