Evaluating the Law of one Price Using Micro Panel Data: The Case of the French Fish Market
利用法国2007年鱼交易微观数据，研究价格空间差异，发现距离和海岸效应可解释部分差异，并基于买卖双方活动识别出大西洋沿岸市场高度整合，价格差异很小，符合一价定律。
This paper investigates spatial variations in product prices using an exhaustive micro dataset on fish transactions. The data includes all transactions between vessels and wholesalers that occurred within local fish markets in France during 2007. Spatial disparities in fish prices are sizable even after taking into account fish quality, time, and unobserved seller and buyer heterogeneity. The price difference between local fish markets can be explained to some extent by distance, but mostly by a coast effect related to market locations on the Atlantic and Mediterranean coasts. We also propose a new approach for identifying groups of interconnected local fish markets based on the activity of sellers and buyers within these markets. We show that most markets on the Atlantic coast are well connected, and that variation in prices across these markets is very small and in line with the law of one price.