Understanding International Price and Consumption Disparities
基于120多种商品的价格离散度提出可贸易性新指标，构建150多个国家的可贸易品与非贸易品价格指数，发现富裕国家可贸易品支出份额更低，非贸易品相对价格更高；通过主成分分析发现价格比消费更具跨国相关性，收入主要解释消费差异而非价格差异。
Abstract This study proposes a new measure of the tradability of 120+ commodities based on price dispersion. This approach is used to construct price indices of tradables and non‐tradables for 150+ countries. The expenditure share of tradables is lower for richer countries, while the relative price of non‐tradables, which plays an important role in the determination of real exchange rates, is higher. Secondly, a common‐factor approach (based on principal components) is introduced to compress the large volume of information on prices and quantities consumed globally. We find that cross‐commodity correlations are higher for prices than for consumption. In addition, income is responsible for most of the variation in the first principal component of consumption but explains less of the first price component. This suggests consumption are driven primarily by domestic factors, while prices are determined by factors outside the country, along the lines of the Purchasing Power Parity theory.