Intercity Distance and Functional Complementarity in Chinese Megaregions

By combining the city attribute data of sectoral employment in producer service and manufacturing and the intercity interaction data of population travel, internet, and patent cooperation from 2015 to 2019, the improved functional complementarity between core cities and their peripheral cities is measured. Using physical distance and expressway length as proxies for intercity distance, the analysis investigates the impact of intercity distance on functional complementarity by taking 11 Chinese megaregions as cases. The empirical results show that: (1) Intercity complementarity decreases with increasing intercity distance. (2) Considering intercity interaction in the measurements reveals the greater sensitivity of intercity functional complementarity to distance. (3) The negative effect of the distance becomes increasingly important over time if the interaction is highly sensitive to distance. (4) Among the sectors examined, leasing and business services show the weakest sensitivity to intercity distance while transportation services exhibit the most sensitivity. Our research emphasizes the significance of intercity distance on intercity functional relations in urban systems.