Export Superstars
研究发现，在32个国家中，最大一家企业平均贡献了该国非石油出口的14%，前五家企业贡献了30%；这些出口超级明星还显著影响行业出口分布，单个企业就能创造该行业的显性比较优势。
We show that very large firms shape country export patterns. Among 32 countries, the top firm on average accounts for 14% of a country’s total (nonoil) exports, and the top five firms make up 30%. These export superstars are also important in the sectoral distribution of exports. Variation in exports from the top firm in a country explains about one-third of the variation in sectoral exports relative to income across countries, and variation in exports from the top five firms explains nearly half. Revealed comparative advantage in a sector can be created by a single firm.