Good news everyone! We all DO have this problem… It’s just most obvious in China because they industrialized and urbanized more rapidly than anyone else AND had this stupid legal policy.
Industrialization, urbanization and improving healthcare also significantly drops births, to below the replacement rate of 2.1. The whole world is on this path, with China, Japan, South Korea, Germany and Russia leading the way.
Common courtesy is to not even link to paywalled articles… The publisher has already made it clear they are not interested in public awareness of their content.