We live in a data-abundant world and yet we lack basic information about inequality. Economic growth numbers are published every year by governments across the globe, but they do not tell us about how growth is distributed across the population – about who gains and who loses from economic policies. Accessing such data is critical for democracy. Beyond income and wealth, it is also critical to improve our collective capability to measure and monitor other dimensions of socio economic disparities, including gender and environmental inequalities. Open-access, transparent, reliable inequality information is a global public good.