We document the evolution of the income distribution across age groups using harmonised microdata from 28 countries at different stages of economic development. While in the last 30 years in rich countries, income has become more concentrated in favour of the old, it has become more concentrated towards the young in lower-income countries. These trends are strong and statistically significant. We investigate further what are the income components that cause those shifts. We highlight that the main contributors are related to labour market dynamics. Specifically, in rich countries, employment rates and salaries are disproportionally augmenting the income of the old compared to the young, while in poorer economies, salaries are growing faster for the young. These results do not depend upon the composition of the workforce (gender, education, sectors). Through a panel regression, we suggest the relevance of three main forces related to ageing, to the education boom, and policymaking, broadly defined.