关键词: 贸易成本, 迁移成本, 全要素生产率, 收入不平等, 全国统一大市场建设

Abstract: Given that China possesses a large and potential domestic market，we present a heterogeneousagent model examining trade and migration patterns among Chinese regions，and analyze the change in income inequality We quantify the internal and international trade costs，total factor productivity （TFP） and internal migration costs using National Census data and Interprovincial Inputoutput data from 2000 to 2015 Our findings indicate that both internal and international trade costs，as well as internal migration costs，have decreased TFP has shown a trend of first increasing and then decreasing，with regional variations
We quantify the impact of these exogenous shocks on national and provincial economic growth and income distribution in China The results show that the decrease in internal and international trade costs and the change in provincial TFP can promote the growth of real GDP However，these shocks may also exacerbate national income inequality，increasing the Gini coefficient by 0020，0010，and 0109，respectively，between 2000 and 2015 Based on Dagums decomposition，interprovincial income inequality is significantly higher，serving as the primary contributor to national income inequality Furthermore，lower migration costs can reduce interprovincial income inequality，with the Gini coefficient decreasing more substantially when interacting with shocks in trade costs and TFP
We further decompose income into labor and capital income，revealing that under exogenous shocks from trade costs and TFP，both labor and capital income inequality tend to widen across provinces，leading to a general rightward shift in income distribution Simultaneous migration cost shocks can reduce interprovincial inequality Additionally，we classify the provinces into four regions—Eastern，Central，Western，and Northeastern—and find regional heterogeneity We also evaluate the heterogeneous effects at the provincial level
The conclusion suggests that it is important to fully recognize the bidirectional role of internal and international trade shocks，along with TFP shocks，in promoting economic growth while also intensifying income inequality It is essential to leverage the potential of Chinas vast domestic market and continuously promote the construction of a unified national market Concurrently，managing the relationship between economic growth and common prosperity is crucial We offer policy insights with the goal of mitigating income inequality and achieving common prosperity through reducing barriers to migration across regions

Key words: trade costs, migration costs, total factor productivity, income inequality, construction of a unified national market