Optimal Tariffs and Market Power: The Evidence
研究发现，在加入WTO前，各国对供给弹性低的进口商品征收的关税比弹性高的商品高9个百分点，市场力量解释了大部分关税差异，且美国未受WTO约束的贸易限制也更多针对其拥有市场力量的商品。
We find that prior to World Trade Organization membership, countries set import tariffs 9 percentage points higher on inelastically supplied imports relative to those supplied elastically. The magnitude of this effect is similar to the size of average tariffs in these countries, and market power explains more of the tariff variation than a commonly used political economy variable. Moreover, US trade restrictions not covered by the WTO are significantly higher on goods where the United States has more market power. We find strong evidence that these importers have market power and use it in setting noncooperative trade policy.