he increasing concentration of wealth and economic power calls for policy action to tame the rise of “private leviathans”. Rabah Arezki, Asif Islam and Grégoire Rota-Graziosi argue that, following commodity booms, regulation, especially pertaining to competition, is found to limit concentration of wealth while taxation has little effect. This is consistent with the primacy of ex-ante (preventive) interventions over ex-post (after-the-fact) ones for addressing wealth inequality.
