Hoarding international reserves versus a Pigovian tax-cum-subsidy scheme: Reflections on the deleveraging crisis of 2008-2009, and a cost benefit analysis

We outline the case for supporting self-insurance by imposing a tax on external borrowing in a model of an emerging market. Entrepreneurs finance tangible investments via bank intermediation of foreign borrowing, exposing the economy to negative fire-sale externalities at times of deleveraging; a risk that increases with the ratio of aggregate external borrowing to international reserves. Price taking economic agents ignore their marginal impact on the expected cost of a deleveraging crisis. The optimal borrowing tax reduces the distorted activity, external borrowing, and induces borrowers to co-finance the precautionary hoarding of international reserves.