China's bullet trains facilitate market integration and mitigate the cost of mega city growth

The advent of bullet trains in China may spur social benefits for the nation’s citizens,a recent study published in PNAS(Proceedings of the National Academy of Sciences of the United States of America,PNAS plus)suggests.The authors,Zheng Siqi(Tsinghua University,China)and Matthew E.Kahn(UCLA,USA)argue that China’s recent investment in"bullet trains"allows individuals to move at speeds of roughly 175 miles per hour and this increases the menu of locations that have access to mega cities.This transportation technology innovation allows individuals to access the mega city without living within its