Airport building spree takes off as 50 Chinese cities reveal hubs plan

More than 50 mainland cities have answered Beijing's call for cleaner economic growth with plans for aviation hubs - airports clustered with industrial zones.

They hope the projects will attract investment in the logistics, high-technology and finance sectors, the sort of businesses Beijing is encouraging as it seeks to move the economy away from an over-reliance on smoke-stack industries.

But critics argue the projects will exacerbate the problem of debt-fuelled construction, which local authorities have used for years to boost their economies.

Such "plans often start high key, but end poorly", government researcher Wang Jun said.

"It is not necessarily a good thing for the whole nation, as so much investment will often lead to overcapacity and increase local government debts," said Wang, who works at the China Centre for International Economic Exchanges. "There are already signs of redundant investment, as some regions in China have too many airports, which are not in full operation."

Wang Xiaohua, an aviation consultant at Kent Ridge Consulting in Fujian, said developing an aviation hub involved more than simply building an airport.

It first of all required minimum annual passenger flows of 10 million and cargo volume of 200,000 tonnes, she said. Only Beijing, Shanghai, Guangzhou, Chengdu, Shenzhen and Kunming met that criteria last year.