Benchmark of the Trends of Spatial Inequality in World Megaregions

There have been growing concerns around the world over the rising spatial inequality (SI) amid fast and vast globalization. This paper presents an effort to benchmark the conditions and trends of spatial inequality in 37 megaregions in the United States, Europe, and China. Furthermore, the study selected three megaregion examples and analyzed the effect of developing high-speed rail (HSR) as an infrastructure investment strategy on reshaping the spatial pattern of job accessibility. The study measures spatial inequality with the Theil index of gross regional product and with the rank-size coefficient of polycentricity. Results show that spatial inequality exists and varies in magnitude within and between megaregions. On average, Chinese megaregions exhibited the level of spatial inequality about two times or more of those in the U.S. and European megaregions. The decade between 2006 and 2016 saw a decrease in the Theil index measure of megaregional inequality in China, but a slight increase in the United States and Europe. Fast growing megaregions exhibit high levels and rising trends of spatial inequality regardless of the country or continent setting. HSR helps improve mobility and accessibility; yet the extent to which HSR reduces spatial inequality is context dependent. This study presents a first attempt to assess and compare the spatial inequality conditions and trajectories in world megaregions aiming at promoting international learning