Moving down the urban hierarchy: Turning point of China’s internal migration caused by age structure and hukou system

Internal migration is critically important in China, where the fertility rate is declining and international immigration is under strict control. This study explores the massive population movement in China, examines the migration pattern of non- hukou migrants, 2010–2015 and 2014–2015 migration patterns through the urban hierarchy of the urban system using migration trajectories derived from the 2015 One Percent Population Sample Survey. Results reveal an emerging reversal from a predominantly upward pattern (e.g. most of the net flows move to high-level cities) to a downward one (e.g. from super-large/extra-large cities to large cities) in the recent migration trend. Regional disparities are significant. An upward and eastward tendency still dominates in the western, central and northeastern regions, whereas a downward and decentralised tendency has been initiated in the eastern region. The causes for the structural change include common factors found in developed countries, such as the influence of age and life courses. The age structure of China’s population caused by the ‘one-child’ policy weakened the upward momentum and led to a strengthening downward trend in the current migration pattern. The contextual and institutional factor hukou also has a significant effect on people’s migration directions. Hukou attracts people to move up or down the hierarchy to their registered place or where they can acquire registration. The characteristics of registered migrants reflect the different criteria of cities in granting hukou.