On the limits of free trade in a Cournot world: When are restrictions on trade beneficial?
研究了在不对称古诺竞争下，小幅进口关税、出口补贴、生产补贴和消费税对国家和世界社会福利及消费者剩余的影响，发现自由贸易通常不是最优的。
Abstract This paper examines marginal deviations from free trade in an asymmetric Cournot world. We provide necessary and sufficient conditions under which: (i) small import tariffs, (ii) export subsidies, (iii) production subsidies and (iv) consumption taxes increase country‐level as well as world social welfare and consumer surplus. We find that free trade is generally not optimal: some countries' tariffs or subsidies can always improve world welfare. Every country's export subsidy raises the average of world social welfare and consumer surplus. Finally, we rank the different policies and show that production subsidies are most likely to raise world social welfare, followed by export subsidies and then import tariffs, whereas consumption taxes never do.