This book summarizes the empirical and theoretical literature on the relation between income inequality and economic growth. The focus concentrates on two approaches: the Political Economy approach and the Capital Market Imperfection approach. The diverging results of these approaches are then combined to a single theory that tries to explain the complex relationship between economic growth and inequality. This should lead to a better understanding of the mechanisms that in uence both, income inequality and economic growth and can help to draw useful policy conclusions.