Recent empirical research on the relationship between income inequality and economic growth has provided controversial results. Some studies predict a negative effect of inequality on growth and some a positive effect. Answers to the controversy have usually been sought in the problems of the estimation technique, the measure of inequality or in some form of non‐linearity in the relationship between inequality and growth. This study accounts for these problems by using an improved measure of income distribution and a parametric group‐related panel estimation. In conclusion, we find that the effect of inequality is likely to be non‐linear. Copyright © 2012 John Wiley & Sons, Ltd.