International trade theorists have long favored free trade, arguing that the only proper basis for a tariff is in response to some monopoly power in international trade. Pragmatic politicians, on the other hand, wary of the wrath of their constituents, have often resorted to the use of tariffs, arguing that the protection afforded by tariffs was necessary to prevent unemployment...
This paper was published in The American Economic Review 66 (1976): 335–346.
Lapan, Harvey E., "International Trade, Factor Market Distortions And The Optimal Dynamic Subsidy" (1976). Economic Staff Paper Series. 182.