Tariff
A tariff is called an optimal tariff if it's set to maximize the welfare of the country imposing the tariff. It is a tariff derived by the intersection between the "trade indifference curve" of that country and the offer curve of another country. In this case, the welfare of the other country grows worse simultaneously, thus the policy is a kind of "beggar thy neighbor policy". If the offer curve of the other country is a line through the origin point, the original country is in the "condition of a small country", so any tariff worsens the welfare of the original country.
Tariff
When tariffs are an integral element of a country's technology strategy, some economists believe that such tariffs can be highly effective in helping to increase and maintain the country's economic health. Other economists might be less enthusiastic, as tariffs may reduce trade and there may be many spillovers and externalities involved with trade and tariffs. The existence of these externalities makes the imposition of tariffs a rather ambiguous strategy. As an integral part of the technology strategy, tariffs are effective in supporting the technology strategy's function of enabling the country to outmaneuver the competition in the acquisition and utilization of technology in order to produce products and provide services that excel at satisfying the customer needs for a competitive advantage in domestic and foreign markets. The notion that government and policy would be effective at finding new and infant technologies, rather than supporting existing politically motivated industry, rather than, say, international technology venture specialists, is however, unproven.