Using a granular model of international trade, we study the rationale and implications of various government interventions targeted at large individual firms. In antitrust regulation, governments face an incentive to be overly lenient towards domestic mergers in comparative advantage sectors. In trade policy, targeting individual foreign exporters rather than entire sectors minimizes the pass-through of import tariffs into domestic consumer prices, shifting the burden towards foreign producers. In industrial policy, subsidizing ‘national champions’ is generally suboptimal in closed economies as it leads to an excessive build-up of market power, yet it may become unilaterally welfare improving in open economies at the cost of the foreign consumers.

使用国际贸易的粒度模型，我们研究了针对大型个体企业的各种政府干预措施的基本原理和影响。在反垄断监管中，政府面临着对比较优势行业的国内并购过于宽容的动机。在贸易政策中，针对个别外国出口商而不是整个行业，最大限度地减少了进口关税对国内消费价格的传导，将负担转移给了外国生产商。在产业政策中，补贴“国家冠军”在封闭经济体中通常是次优的，因为它会导致市场力量的过度建立，但它可能会以牺牲外国消费者为代价，在开放经济体中单方面改善福利。