Competition, Markups, and the Gains from International Trade

摘要《竞争、加价和国际贸易的收益》NSF提案Chris Edmond，Virgiliu Midrigan，Daniel Xu这个项目研究了消除国际贸易壁垒的政策对竞争的影响。大多数现有的研究集中在国际贸易的收益上，这些收益来自于增加的专业化或消费的多样性。该项目侧重于另一种机制，即当国际贸易壁垒减少时，国内生产者面临的竞争增加。从理论上讲，更激烈的竞争可能会导致国内生产商加价(价格-成本边际)的下降和加价差异的缩小，从而导致生产、就业和效率的增加，并带来巨大的潜在福利收益。该项目旨在通过结合理论和来自一些经历了贸易自由化的国家的公司层面的数据来衡量这一机制的力量。衡量加价对贸易自由化的反应是一项困难的任务，因为通常无法获得有关加价的数据。这个项目试图通过结合最新的加价确定理论模型和来自产业组织领域的最先进的估计技术来仔细估计生产者层面的成本和加价，从而在这一维度上取得进展。该项目使用几个信息来源来衡量加价对贸易壁垒变化的反应。该项目利用的一个信息来源是价格-成本利润率与单个生产商面临的竞争程度之间的关系，这是通过生产商在本行业的市场份额来衡量的。由于价格-成本利润随竞争程度的不同而变化很大，贸易壁垒的减少，通过增加竞争，可以对国内加价的平均水平产生重大影响。该项目利用的第二个信息来源是价格-成本差值对贸易自由化个别事件的反应。通过利用各种贸易协定(如北美自由贸易协定)对不同行业贸易模式和价格-成本利润率的不同影响，该项目可以揭示贸易自由化的个别事件对美国和其他国家不同行业的竞争程度和加价水平的影响。该项目的发现具有超越国际贸易的影响，并将阐明加价对跨国收入差异和商业周期波动的作用。跨国收入的差异在一定程度上反映了资源在不同生产者之间分配效率的差异。加价的差异可能是分配效率低下的一个重要来源，该项目将检查情况是否确实如此。加价波动也可能在解释金融危机后美国就业率近期大幅下降的原因中发挥重要作用，更广泛地说，是在经济活动出现大幅收缩的情况下。这种衰退通常伴随着劳动力收入份额的大幅下降。这种下降是因为生产者加价的增加，还是劳动力市场的低效，这是一个重要的问题，该项目将通过研究大规模衰退和金融危机期间的生产者层面的数据来解决这个问题。

Abstract"Competition, Markups, and the Gains from International Trade"NSF ProposalChris Edmond, Virgiliu Midrigan, Daniel XuThis project studies the pro-competitive effects of policies that eliminate barriers to international trade.Most existing research focuses on gains from international trade that arise from increased specialization or from increased diversity in consumption. This project focuses on an alternative mechanism, namely the increase in the amount of competition domestic producers face when international trade barriers are reduced. Greater competition can lead, in theory, to a drop in markups (price-cost margins) and in markup differences across domestic producers, thereby leading to an increase in production, employment and efficiency and large potential welfare gains. This project aims to measure the strength of this mechanism by combining theory and firm-level data from a number of countries that have experienced trade liberalizations. Measuring the response of markups to trade liberalizations is a difficult task since data on markups is generally unavailable. This project seeks to make progress on this dimension by combing recent theoretical models of markup determination with state-of-the-art estimation techniques from the field of industrial organization to carefully estimate producer-level costs and markups. The project uses several sources of information to measure the response of markups to changes in trade barriers. One source of information the project exploits is the relationship between price-cost margins and the amount of competition individual producers face, as measured by a producer's market share in its own industry. To the extent to which price-cost margins vary a lot with the amount of competition, a decrease in trade barriers, by increasing competition, can have a significant effect on the average level of domestic markups. A second source of information the project exploits is the response of price-cost margins to individual episodes of trade liberalizations. By exploiting the differential impact of various trade agreements (such as NAFTA) on different industries' trade patterns and price-cost margins, the project can shed light on the effect individual episodes of trade liberalizations have had on the amount of competition and the level of markups in different industries in the US and other countries.The project's findings have ramifications beyond international trade and will shed light on the role of markups for cross-country income differences and business cycle fluctuations. Cross-country differences in income reflect, in part, differences in the efficiency with which resources are allocated across producers. Differences in markups may be an important source of allocative inefficiency and the project will examine whether this is indeed the case. Markup fluctuations may also play an important role in explaining the large recent drop in US employment in the aftermath of the financial crisis and more generally around episodes of large contractions in economic activity. Such recessions are typically associated with large declines in labor's income share. Whether such declines are accounted for by an increase in producer markups, or inefficiencies in the labor market is an important question that the project will address by studying producer-level data during episodes of large recessions and financial crises.