Environmental Policies, Comparative Advantage and the Gains/Losses from International Trade

A multihousehold economy with multilateral nondepletable externalities, environmental (output) taxation and governmental production of pure, nonexclusive and nonrivalrous public goods is assumed. Modelling many different households the "almost perfect" isomorphism between the normative analysis of public goods and environmental policies is highlighted. Globally valid necessary and sufficient conditions for gains from international trade are derived and interpreted. A simple yet general environmental policy rule ensuring trade gains is put forward. The law of comparative advantage is generalized to economies with multilateral nondepletable externalities and over or underproduced pure public goods.