Inequality has emerged as a major source of concern for people all over the world who find it unacceptable that poverty should persist in a world of plenty. Reducing inequality is needed - first and foremost - in order to fulfil people's universal aspiration to dignity and respect. But there are also more instrumental reasons to address excessive and growing inequalities as the high levels of inequality are detrimental to economic growth and limit growth's potential to eliminate poverty. However, the experience of many countries that have managed to significantly reduce gaps in human wellbeing over the last decade shows that the political space for resolute action can be created. This Report represents an important contribution to this debate and, as such, it will assist policy makers in identifying pathways towards greater social justice, prosperity and sustainability.