Quantifying Inter-regional Trade Inequality of China's Cities Based on Environmental-economic Benefits in Virtual Built-up Land Flow

The development of spatial interactions of land resources enhances virtual built-up land flow, which contributes to China's inter-regional trade inequality. Little is known about the degree of inequality among regions. This work seeks to estimate the degree of interregional trade inequality through environmental-economic benefits. We combined a multiregional input–output model at the city level with a new classification to calculate the virtual built-up land flow among cities and analyzed its implications for the regional economy and carbon balance. The results indicate that developed regions were the main beneficiaries of inter-regional trade, as reflected in land-use efficiency. China's economic hub has been progressively shifting southward, and the inter-regional trade inequality has continuously increased. The flow of virtual service industry land among developed regions rose, while underdeveloped regions remained suppliers of raw materials, further increasing inter-regional trade inequality.