Deforestation is a phenomenon that has largely been concentrated in the developing world. We construct a theoretical model of deforestation that focuses on the factors affecting the incentives to transform forested land into agricultural land. We show that: (i) lower discount rates and stronger institutions decrease deforestation; (ii) a depreciation in the real exchange rate increases deforestation in developing countries whereas the opposite obtains in developed countries; (iii) paradoxically, better institutions may exacerbate the deleterious impact of a depreciation in developing countries. These hypotheses are tested on an annual sample of 101 countries over the 1961–1988 period, and are not rejected by the data. Our results suggest that short-term macroeconomic policy, institutional factors, and the interaction between the two, are potentially important determinants of environmental outcomes.