Collaborative Research: Worker Adjustment to International Trade: Evidence from Administrative Data

《工人对国际贸易的适应：来自管理数据的证据》，麻省理工学院的David H.Autor和NBER的Gordon H.Hanson，UCSD和NBER。经济理论表明，通过允许各国根据其比较优势进行专业分工，国际贸易使消费者能够获得更多种类的产品，从而提高他们的实际收入。随着工人从与进口竞争的部门转移到其他活动中，实现这些收益往往会带来国家产业结构的重大变化。关于全球化的公众辩论倾向于更多地关注工人、公司和行业从调整到进口竞争的短期成本，而不是贸易的长期好处。因此，确定与贸易相关的调整成本对于制定有关全球经济一体化的政策讨论非常重要。该项目研究了长期暴露在进口竞争中对美国工人就业和收入轨迹的影响。焦点是美国从中国进口的增长，尽管从其他低工资国家的进口也被考虑在内。为了衡量工人的结果，该项目使用了1978年至2007年期间社会保障管理局(SSA)的个人数据。SSA数据包含按雇主和行业分列的工人年收入的完整历史，以及有关领取社会保障福利的信息。通过这些数据，可以估计进口竞争如何影响企业和部门的工人就业、收入和福利吸收，以及这些结果如何根据工人的人口统计特征(年龄、性别、种族、族裔、外国出生身份)、技能水平和雇主特征而变化。在分析失业对工人收入的影响时，行政数据被广泛使用，但在考虑美国贸易的后果时，这些数据没有得到充分利用。因此，该项目将为美国工人之间的贸易长期调整提供证据，而不是文献中所缺失的证据。促使人们关注中国的是该国惊人的经济增长，特别是制造业。自20世纪90年代初以来，中国贡献了中低收入国家制造业增加值增长的近四分之三。对美国来说，中国的影响再加上两国进出口总额的严重不平衡。中国有很大的贸易顺差，而美国有很大的贸易逆差。因此，受到中国贸易能力增加影响的美国行业，在供应方面面临着全球竞争的大幅扩大，而在需求方面，消费者对其产品的支出却没有得到抵消。中国的出口增长似乎在很大程度上归功于其国内工业生产率的显著提高，这是由于国家管制的解除以及贸易和投资限制的放开。该项目将两个完全不同的知识体系结合在一起。一个是关于国际贸易如何影响劳动力市场，通过研究受影响的公司、行业或地区的这些变化，研究进口竞争的变化如何在短期或中期改变工资和就业。虽然这种方法揭示了进口竞争加剧的暂时影响，但它忽略了个人离开公司、放弃行业或搬迁到另一个城市或州后对工人的影响。通过利用SSA数据中提供的关于工人个人的长期数据，该项目捕捉到与中国贸易的增加如何改变工人在最初的公司受雇时、在同一行业的新公司工作后、在完全转移到一个新行业后以及在完全退出工作后的收入和社会保障福利。将收入的长期变化分解为这四个组成部分，显示了在转型过程中，工人面临的调整成本最大的地方，这一结果将有助于指导未来关于贸易和劳动力市场的理论工作。第二篇相关文献追踪失业工人的收入。由于非自愿失业很难在现有数据中识别，许多研究使用行政记录来隔离极端的流离失所案例，例如与工厂关闭或大规模裁员相关的大规模裁员。文献表明，大规模裁员导致的失业对工人收入具有显著的负面长期影响。通过使用行政数据，该项目像早先的失业工人文献一样，捕捉到了劳动力市场条件变化的长期影响。通过聚焦于一种特定类型的变化，即与中国更激烈的进口竞争有关的变化，该项目审查了与贸易有关的所有类型的失业，而不仅仅是与大规模裁员相关的失业。

Worker Adjustment to International Trade: Evidence from Administrative DataDavid H. Autor, MIT and NBERGordon H. Hanson, UCSD and NBERAbstract. Economic theory suggest that by allowing countries to specialize according to their comparative advantage international trade gives consumers access to a greater variety of products, raising their real incomes. Realizing these gains often brings about substantial changes in national industry structure, as workers move out of import-competing sectors and into other activities. The public debate about globalization tends to center less on the long-run benefits of trade and more on the short-run costs of workers, firms, and industries from adjusting to import competition. Characterizing the adjustment costs associated with trade is therefore important for framing the policy discussion about global economic integration.This project examines the impact of exposure to import competition on the employment and earnings trajectories of U.S. workers over the long term. The focus is on growth in U.S. imports from China, though imports from other low-wage countries are also considered. To measure worker outcomes, the project makes use of individual-level data from the Social Security Administration (SSA) over the period 1978 to 2007. The SSA data contain a complete history of a worker's annual earnings by employer and by industry, as well as information on receipts of Social Security benefits. These data make it possible to estimate how exposure to import competition affects worker employment, earnings, and benefits uptake by firm and by sector and how these outcomes vary according to a worker's demographic characteristics (age, gender, race, ethnicity, foreign-born status), skill level, and employer characteristics. Administrative data have been used extensively in the analysis of the impact of job loss on worker incomes, but they have been underutilized in considering the consequences of U.S. trade. The project will thus provide evidence on long-run adjustment to trade among U.S. workers than is missing in the literature.Motivating the focus on China is the country's spectacular economic growth, particularly in manufacturing. Since the early 1990s, Chinas has accounted for nearly three quarters of the growth in manufacturing value added by low and middle income countries. For the United States, China's impact is compounded by a profound imbalance in the two countries' aggregate exports and imports. China runs a large trade surplus, whereas the U.S. runs a large trade deficit. U.S. industries exposed to the increase in China's trade capacity have consequently faced a major expansion in global competition on the supply side, without an offsetting expansion in consumer spending for their products on the demand side. China's export growth appears to be largely attributable to its remarkable improvements in domestic industrial productivity arising from the dismantling of state control and the liberalization of restrictions on trade and investment. The project unites two disparate bodies of knowledge. One, on how international trade affects labor markets, examines how changes in import competition alter wages and employment in the short or medium run by studying these changes in impacted firms, industries, or regions. While this approach uncovers the temporary effects of greater import competition, it misses impacts on workers that persist after an individual leaves his firm, abandons his industry, or relocates to another city or state. By utilizing long-run data on individual workers available in the SSA data, the project captures how increased trade with China changes earnings and uptake of Social Security benefits that workers experience while employed at their initial firm, after they move to a new firm in the same industry, after they shift to a new industry altogether, and after they exit from employment entirely. Decomposing the long-run change in earnings into these four components shows where in the transition process workers face the most significant adjustment costs, results that will help guide future theoretical work on trade and labor markets. The second body of related literature tracks the earnings of workers who are displaced from their jobs. Because job loss that is involuntary is difficult to identify in available data, much research uses administrative records to isolate extreme cases of displacement, such as mass layoffs associated with plant closures or substantial downsizings. The literature shows that job loss due to mass layoffs has significant negative long-run effects on worker earnings. By using administrative data, the project, like the earlier displaced-worker literature, captures the long-run effects of changes in labor-market conditions. By focusing on a specific type of change, namely one related to greater import competition from China, the project examines all types of job loss related to trade and not just those associated with mass layoffs.