Collaborative Research: Geography, Trade, and Prices

地理、贸易和价格SBE-SES 0820536和0820462布罗达和温斯坦合作几乎所有解释美国人为什么从国际贸易中受益或损失的核心都是一个概念，即外国商品应该通过影响国内价格来影响企业和消费者。不幸的是，数据并不支持这些理论。研究一再发现，国内价格几乎不受外国价格的影响。因此，一个人留下了一个悖论。尽管坊间传闻全球化似乎正在对美国经济产生深远影响，但数据似乎表明，我们的边境几乎完全不受外国价格波动的影响。我们的项目通过使用大量的美国和加拿大条形码数据解决了这个难题。以前的研究依赖于政府计算的价格指数或私营部门对商品的价格调查，这些指数不一定具有国际可比性。我们的条形码数据显示，美国各城市消费的商品集合存在很大的异质性，即使是在定义极其狭隘的产品类别中，如“牛奶”。这种异质性使生产商能够在不同的空间对这些商品收取不同的价格，并在很大程度上使它们不受其他生产商收取的价格变化的影响。并不令人意外的是，加拿大和美国的商品消费构成也存在很大差异。品牌和型号的差异如此之大，以至于所消费的商品中只有大约10%是相同的。这两个事实有助于解释为什么在以前的工作中边界如此之大。在比较各国的综合指数时，研究人员通常会比较基本不相交的几组商品的平均价格变动。可口可乐在美国的价格走势可能完美地反映了可口可乐在加拿大的走势，但如果加拿大统计局只将RC可乐纳入其价格指数，其影响似乎要小得多。我们的初步结果表明，同一商品的国际价格差异往往只比国内略大，但如果使用(较差的)数据来比较一国的一套商品和另一套不同国家的商品，那么国界似乎要大得多。商品的这种异质性也有助于我们理解价格冲击是如何跨境传播的。条形码数据再次表明，边界在该传输中的重要性很大程度上是由于聚合偏差。如果你将相同的商品进行对比，加拿大的价格变化很快就会转化为美国的价格变动。换句话说，该项目表明，国际价格变动对美国价格产生了快速而巨大的影响。然而，如果使用指数来研究价格传导，就会得出相反的结论。我们打算通过发表文章和参加会议来传播这项研究的结果。此外，我们将与统计机构和货币当局合作，帮助改进价格衡量和政策制定。这项研究还将具有跨学科/跨机构的维度。其中一些工作将与农业部的Ephraim Leibtag博士联合进行。我们希望我们的工作将有助于那些有兴趣了解全球化对非熟练工人的影响以及对定价行为的影响的人。

Geography, Trade, and PricesSBE-SES 0820536 and 0820462Broda and Weinstein, CollaborativeAt the heart of almost all explanations of why Americans benefit or lose from international trade is a notion that foreign goods should affect firms and consumers through their impact on domestic prices. Unfortunately, the data has not been kind to these theories. Studies have repeatedly found that domestic prices are hardly affected by foreign prices. Thus, one is left with a paradox. Although globalization seems anecdotally to be exerting profound effects on the US economy, the data seems to indicate that our borders insulate us almost completely from foreign price movements. Our project solves this puzzle by using vast amounts of US and Canadian barcode data. Previous studies relied on price indexes computed by governments or private price surveys of goods that were not necessarily internationally comparable. Our barcode data reveals that there is substantial heterogeneity in the set of goods consumed across cities in the US, even in extremely narrowly defined product categories such as "milk". This heterogeneity enables producers to charge different prices for these goods across space and substantially insulates them from price changes charged by other producers. Not surprisingly, there are also substantial differences in the composition of goods consumed in Canada and the US. Brands and models differ to such an extent that only about 10 percent of the goods consumed are identical. These two facts help explain why borders loomed so large in previous work. When comparing aggregate indexes across countries, researchers typically compared average price movements of largely disjoint sets of goods. Movements in the price of Coca Cola in the US might perfectly mirror movement of Coca Cola in Canada, but if Statistics Canada were only including RC Cola in their price indexes, the effects would appear much smaller. Our preliminary results suggest that international price differences for the same good tend to be only slightly larger across borders than they are within countries, but the borders seem much larger if one uses (poor) data that compares one set of goods in one country with another set of goods in a different country. This heterogeneity of goods also helps us to understand how price shocks are transmitted across borders. Again the barcode data reveals that much of the importance of the border in this transmission is due to an aggregation bias. If one compares identical goods across the border, price changes in Canada translate very rapidly into price movements in the US. In other words, the project demonstrates that international price movements have rapid and large impacts on US prices. However, if one were to look at price transmission using indices, one would obtain the opposite conclusion. We intend to disseminate the results from this research through the publication of articles and the participation in conferences. Moreover, we will work with statistical agencies and monetary authorities to help improve the measurement of prices and formulation of policy. This research will also have a cross-disciplinary/cross-institutional dimension. Some of the work will be joint with Dr. Ephraim Leibtag at the Department of Agriculture. We expect that our work will be useful for people interested in understanding the impact of globalization on unskilled workers as well as on pricing behavior.