Thirty years ago, the eastern coast of Tianjin was a patch of deserted land with a few scattered factories. Now it is home to more than 14,000 companies, 5,000 of which are foreign-funded.

“When China first decided to set up a development zone here, people had doubts about how it would progress and how far it could go,” said Xu Hongxing, director of the Tianjin Economic-Technological Development Area.

Various kinds of development have since affected the economy in ways far beyond the expectations of the time. They have generated plenty of growth, but the question arises about whether the policy is still on track.

“Economic zones ... have played a crucial role in increasing trade, creating jobs, driving growth, and most important, connecting China with the rest of the world,” said Chen Qining, president of the China headquarters of Singapore SCP Consultants Private Ltd, a city and regional planning consultancy.

The Tianjin Economic-Technological Development Area was one of the first approved in 1984 to expand reform and opening-up.

By this past July, there were 215 economic and technological zones, 115 high-tech zones, 13 tariff-free zones, 63 export processing zones, 15 border zones, and 57 zones of other types. In addition to these national zones, there were 1,170 provincial zones and numerous prefecture- or county-level economic zones.

One-fifth of gross foreign investment has gone into 210 national economic and technological development zones that contributed one-eighth of GDP in 2013.

However, Wang Jici, of Peking University’s College of Urban and Environmental Science, said, “If you look at the development of economic zones, there were problems like low efficiency, over-exploitation of resources, environmental pollution and corruption.”

Many of the 171 state-level economic zones in 2012 reported less than 50 billion yuan ($8.14 billion) in GDP and no more than 20 billion yuan in exports.

Under the control of local governments, the zones have often become hotbeds of corruption.

And local officials obsessed with GDP are inclined to tolerate high-polluting industries.

Vice-Premier Wang Yang has advocated a new approach to the zones.

“The government will strengthen macro-guidance and dynamic management, downgrading or weeding out those zones that are inefficient in land use or backward in development, and that fail to meet environmental standards,” the vice-premier said recently.