I use bilateral trade data from a variety of countries to decompose the patterns of trade growth across various goods classifications during episodes of rapid growth in bilateral trade. I find that bilateral trade growth during these episodes is fragmented—less than 5% of goods classifications account for over 65% of overall bilateral trade growth. I quantitatively assess whether “Melitz‐style" trade models, with heterogeneous productivity firms, CES demand and fixed and variable costs of exporting, can match the observed fragmentation of bilateral trade growth. I find the standard model generates less than 40% of the observed fragmentation in the data, as measured by the share of total trade growth accounted for by various quantiles of goods classifications. However, by incorporating heterogeneous tariff and productivity changes imputed from US production and export data, I find that the model generates approximately 90% of the magnitude of fragmentation of trade growth across goods as in the data.

中文翻译：

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分解国际贸易大幅增长的情况

我使用来自不同国家的双边贸易数据来分解双边贸易快速增长时期各种商品类别的贸易增长模式。我发现这些时期的双边贸易增长是零散的—不到5％的商品分类占双边贸易总额增长的65％以上。我定量评估了“梅里兹式”贸易模型（具有异质生产力公司，CES需求以及固定和可变出口成本）是否可以与观察到的双边贸易增长分散相匹配，我发现标准模型所产生的观察值不到观察值的40％数据的零散，以各种商品分位数所占贸易总增长的份额来衡量，但是，通过结合从美国生产和出口数据推算得出的异构关税和生产率变化，我发现该模型产生了约90％的如数据所示，跨商品贸易增长的分散程度。