The article explores how income inequality affects economic growth. It presents two models: one showing how policies like taxes and public schooling can impact savings and investment, and another showing how conflict can hinder property rights and accumulation. The research finds that the economy grows slower when interest groups have more power and when the gap between rich and poor is wider. The key is not just income inequality, but also inequality in earning and political power. The study also questions whether differences in inequality between countries are permanent or narrowing over time.