Journal article: The evolution of labour market and disposable income inequalities over recent decades in high‐income countries has generated intense interest in academia and the wider public. The extent to which there have been common trends, or diverging experiences, across a broad range of different countries, remains relatively understudied. The papers in this two‐part special issue seek to provide the bases for consistent comparisons across 17 North American and European countries. In this Introduction we provide background for the cross‐country project, which has been conducted in parallel to the wider IFS Deaton Review of Inequalities. In addition, we provide brief summaries of key trends and findings in the four English‐speaking countries and four Nordic countries, as well as a companion paper on gender pay gaps across all 17 countries.