Quality trade and transportation costs
利用2014-2020年海关申报数据，发现高质量产品单位运费更高、从价税率更低，且更多与高人均GDP国家贸易。
This study investigates quality trade using a declaration level customs dataset from 2014 to 2020. We find that high quality products tend to be traded with higher per-unit freight costs, lower ad valorem tariff rates, and with countries with higher GDP per capita, even after controlling firm-specific and product-specific time-invariant factors.