This paper explores the interplay between concentration of wealth and policies, namely regulation and taxation. The paper exploits variation in exposure to international commodity prices. Using a global panel data set of the net worth of billionaires, the results point to a positive relationship between commodity prices and the concentration of wealth at the top. Regulation especially pertaining to competition is found to limit the effects of commodity price shocks on the concentration of wealth, while taxation has little effect. Moreover, commodity price shocks crowd out non-resource tax revenue, hence limiting the scope for income transfers and redistribution. The results are consistent with the primacy of ex ante interventions over ex post ones for addressing wealth inequality.