That artificial growth comes from reporting GDP on building things that nobody uses (like Cities). Conversely, like a large private corporation which doesn't have to reveal costs in any general accounting rules kind of way, China has the ability to create a view of their economy which is 'untrue.'
So put another way, the author posits that in a market economy the creation of a new city would be done by actors who were themselves creating more economic output as a result of productivity gains from having city infrastructure. Thus economists see new building as a leading indicator of economic growth. However if you simply spend a billion dollars to build a high rise office tower without any tenants or even a prospect of leasing it out, the 'leading indicator' aspect of that data point is completely wrong. The building will sit there empty, generating no economic growth whatsoever. There are hints that China is manipulating its figures in just that way.
The bigger challenge for China is that in the eastern part of the country the standard of living is growing much more rapidly than it is for people living in the western half of the country. The last time that happened Mao Tse Tung used it to his advantage to overthrow the incumbent government.
