This paper examines the effects of tariffs and quotas on the pricing pattern of producers in the case of duopoly by a domestic monopolist and a foreign monopolist. It is pointed out that tariffs and quotas may induce completely different pricing patterns in the two producers. Under a quota, it is always profitable for the home producer to be a price leader and for the foreign producer to be a follower, whereas under a tariff either producer may become a leader. It is also proved that, whatever leader-follower relation is chosen under a tariff, a quota always bring about a higher domestic price than the tariff as long as both permit the same amount of imports.

In oligopolistic situations, content protection can have unexpected effects as it changes the nature of interactions between input suppliers. With a duopoly, it does so in a manner that makes the foreign firm wish to match price increases and decreases of the domestic firm. Domestic input suppliers can therefore lose from such policies, even when set at free trade levels. The relation between input demands, the form of protection, and the degree of substitution between inputs is shown to define the effects of content protection and to provide the basis for understanding who might lobby for protection in different environments.