In the three decades to the recent economic downturn, wage gaps widened and household income inequality increased in a large majority of OECD countries. This occurred even when countries were going through a period of sustained economic and employment growth. This report analyses the major underlying forces behind these developments. It examines to which extent economic globalisation, skill-biased technological progress and institutional and regulatory reforms have had an impact on the distribution of earnings. The report further provides evidence of how changes in family formation and household structures have altered household earnings and income inequality. And it documents how tax and benefit systems have changed in the ways they redistribute household incomes. The report discusses which policies are most promising to counter increases in inequalities and how the policy mix can be adjusted when public budgets are under strain.