Government policies in a granular global economy
用颗粒化国际贸易模型研究针对大企业的政府干预，发现反垄断在比较优势部门偏宽松、贸易政策针对单个外国企业可降低关税对国内价格的影响、产业政策补贴国家冠军在开放经济中可能改善本国福利但损害外国消费者。
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.