The permanent income rule is seldom the optimal response to a windfall of foreign exchange, such as that from a resource discovery. Absorptive capacity constraints require domestic investment, and investment in structures requires non-traded inputs the supply of which is constrained by the...

Where imports are financed predominantly by rents from resource extraction or aid the revenue generated by tariffs is illusory. Revenue earned by the tariff is offset by a reduction in the real value of aid and resource rents. Revenue is however moved between accounts in the government budget...