網絡外部性對於福利極大與收入極大關稅排序之影響

The Effect of Network Externalities on Social Welfare Maximization and Revenue Maximization Tariff Ranking

本文在存在網絡外部性以一家本國廠商及一家外國廠商的寡佔市場中，探討政府對於社會福利極大與關稅收入極大的關稅排序的重要問題。結果發現，由於網路外部性越大，外國進口產品，對於消費者福利的提升效果越強；此時為提高社會福利，政府應調降關稅，促進外國產品的進口。因此，越容易發生福利極大化關稅稅率低於收入極大化關稅稅率。

This paper discusses the issue of the government's ranking of tariffs with maximum social welfare and maximum revenue in an oligopolistic market with one domestic firm and one foreign firm with network externalities. The results show that the greater the network externalities, the greater the effect of import on improving consumer welfare; in order to improve social welfare, the government should lower tariffs and promote the import of foreign products. Therefore, it is more likely that the welfare-maximizing tariff rate will be lower than the revenue-maximizing tariff rate.