Disguised Protectionism, Global Trade Rules and Alien Invasive Species

Current international law strongly favors policies designed to make imports safer (e.g., in terms of invasive species) over policies explicitly designed to discourage imports. We show that this preference may be counterproductive. A externality in trade is incorporated into a political-economy model of policy formation. Nations can address the externality by inspecting cargo and imposing a fine on contaminated imports. We compare the equilibrium when inspection is the only policy option relative to the equilibrium that emerging when nations may also manipulate the tariff. Ruling out the tariff causes socially excessive stringency in general, social welfare losses if domestic supply is highly inelastic, and in some circumstances an increase in the real tariff, measured as the difference between world and domestic prices.