Antoine Bozio, a leading economist focused on tax issues concerning the ultra-rich in France, engages in a thought-provoking discussion. They explore how data scarcity complicates understanding the tax obligations of billionaires. The conversation highlights disparities between tax policies and actual tax burdens faced by the wealthy and scrutinizes the adequacy of the current tax regime. Bozio also examines proposed reforms aimed at enhancing progressivity in taxation while tackling the challenges wealthy individuals present in navigating tax laws.