The pro-competitive effects of trade agreements
利用11个中低收入国家企业产品出口数据，发现贸易协定下的关税削减鼓励企业进入并降低出口商的加价，这与标准寡头竞争模型预测相反。
How does trade policy affect competition? Using the universe of product exports by firms from eleven low and middle-income countries, we document that tariff reductions under trade agreements have strong pro-competitive effects - they encourage entry and reduce the (tariff exclusive) price-cost markups of exporters. This finding, that markups fall with tariff cuts, contradicts a core prediction of standard oligopolistic competition models of trade. We extend a workhorse international pricing model of oligopolistic competition to include multiple countries and a rich preference structure. Our preference structure allows for fierce competition among firms from the same country and less intense competition among firms from different countries. We show a firm's optimal markup after a tariff cut can rise or fall depending on the parameters of the preference structure and tari-induced reallocation of market share among firms and across countries.