Collaborative Research: International Prices, Costs and Markups

国际价格、成本和涨幅SBE/SES 0820468：美食市场如何运作和套利的限度是许多经济学领域的核心问题。在国际经济学的背景下，这些问题的形式是确定由国家边界分隔的市场比一个国家内的区域市场更多还是更少地分割。试图回答这个问题的实证文献面临两个重要挑战。首先，实证检验要求所比较的商品是相同的。其次，在没有成本或利润数据的情况下，很难确定价格细分的证据是否表明不同地点的制造商或零售商的成本存在不同的加价或差异。这两个限制都在本项目中得到解决。PI使用一个新的机密数据集，其中包含来自北美最大的食品和药品零售商之一的详细产品级别(UPC或条形码)信息，该零售商的门店位于美国和加拿大。该数据集包含2004：1至2007：6(178周)期间在美国250家门店(19个州)和75家加拿大门店(5个省)销售的6347种商品的每周数据。由于数据集包含有关商品价格、售出数量和成本的信息，采购指数可以将不同地点的相对价格变化分解为当地的相对成本和相对加价部分。除新数据外，PIs还建议使用一种新的方法来估计边界的经济重要性，该方法借鉴了治疗效果文献，即回归间断设计。这种设计利用了商店的精确位置和它们到边境的距离。初步结果显示，美国境内、加拿大境内和跨境两地的价格行为存在显著差异。跨境商店的绝对价差中值是美国国内商店的两倍。随着时间的推移，估计的边界效应与美国-加拿大的名义汇率密切相关。这些研究结果对于了解实际汇率波动的来源、货币、财政和技术冲击在各国之间的传递以及名义汇率变动对相对价格的影响，进而对外部收支调整的影响，具有重要意义。

International Prices, Costs and MarkupsSBE/SES 0820468: GourinchasThe questions of how markets function and the limits to arbitrage are central for many areas in economics. In the context of international economics, these questions take the form of determining whether markets separated by country borders are more or less segmented than regional markets within a country. The empirical literature that attempts to answer this question faces two important challenges. First, empirical tests require that the goods compared are identical. Second, without data on costs or profits, it is difficult to ascertain whether evidence of price segmentation indicates varying mark-ups or differences in manufacturers' or retailers' costs across different locations.Both limitations are addressed in this project. The PIs use a new confidential dataset with detailed product-level (UPC or barcode) information from one of the largest North American food and drug retailers, with stores located in the United States and Canada. The dataset contains weekly data on 6347 goods sold in 250 US stores (in 19 states) and 75 Canadian stores (in 5 provinces), between 2004:1 and 2007:6 (178 weeks). Since the dataset contains information on prices, quantities sold and cost of goods, the PIs can decompose variations in relative prices across locations into their local relative costs and relative mark-up components. Besides new data, the PIs propose to estimate the economic importance of the border using a new methodology, borrowed from the treatment effects literature, namely a regression discontinuity design. This design exploits the precise location of stores and their distance to the border. Preliminary results indicate significant differences in the behavior of prices within the United States, within Canada, and across cross-border pairs. The median of the absolute price gap is twice as large for cross-border stores as compared to within-US pairs. The estimated border effect over time is found to co-move closely with the US-Canada nominal exchange rate. These finding are important for understanding the sources of fluctuations in real exchange rates, the transmission of monetary, fiscal and technology shocks across countries and the impact of nominal exchange rate movements on relative prices and consequently on the adjustment of external balances.