This paper addresses the effectiveness of tariff policy in the long-run pro
duction framework in which decisions must be made about plant size and the
level of output to be produced by foreign duopolists competing with each ot
her in the importing country's market. We consider two types of tariff regi
me, discriminatory and uniform, and show that the importing country's welfa
re is unambiguously higher in the uniform tariff case. We consider free tra
de in the same production framework and show that, as the longrun capacity
decision becomes increasingly relevant relative to the short-run quantity d
ecision, free trade dominates tariffs in welfare rankings.