"This paper investigates the relationship between natural resources and capital flight in the form of tax avoidance from multinational corporations. In particular, it focuses on the spillover effects in terms of tax revenue mobilization and stock market development from the thin capitalization rule, a policy instrument aimed at limiting firm tax avoidance through setting limits on a firm’s foreign indebtedness. We exploit the plausibly exogenous within-country variations of data on oil discoveries for a panel of 117 countries during the period 1970–2012. We find evidence that oil discoveries significantly enhance both tax revenue mobilization and stock market development, but only when a thin capitalization rule is in place. We argue that these findings can be explained through the limiting role of a thin capitalization rule in multinational companies’ use of financial transactions among their affiliates or tax havens to transfer part of the profit. The thin capitalization rule may thus not only help limit the erosion of the domestic tax base but may also entice multinational corporations to resort to using and developing the domestic financial system."