Impact of Express Delivery Industry's Development on Transportation Sector's Carbon Emissions: An Empirical Analysis from China

In recent years, China's express delivery industry has developed rapidly. According to a rough estimate in this paper, carbon emissions caused by express parcel transportation in China account for 1/7 of the transportation sector's carbon emissions. However, considering the possibility of a scale effect, it is unclear whether the express delivery industry's development will inevitably lead to more carbon emissions. Therefore, this paper uses the panel data of 30 Chinese provinces from 2008 to 2017 to explore the complex relationship between the express delivery industry's development and the transportation sector's carbon emissions, and also conducts regional heterogeneity analysis. The main findings are as follows: (1) There is a significant U-shaped relationship between per capita express delivery amounts and the transportation sector's CO2 emissions, especially in the Central region. (2) At the national level, the number of per capita postal outlets significantly promotes the transportation sector's CO2 emissions. (3) The impact caused by the number of per capita postal workers varies regionally. Increasing postal worker numbers in the Western region can significantly reduce carbon emissions, while the result in the Central region is the opposite. (4) The Express Comprehensive Development Index (ECDI) has a significant U-shaped effect on the transportation sector's carbon emissions at the national and sub-regional level.