Foriegn Policy says:
The recklessness can be traced to two things: First, local Chinese officials are evaluated for promotions and other rewards based on how well the economy they manage performs. Construction and real estate activities are among the most straightforward ways to stimulate growth. White-elephant construction projects thus offer eager officials a perfect opportunity to impress their political superiors, even if massive developments do not necessarily make any economic sense. Take, for example, the city of Ordos in Inner Mongolia: Its elaborate urban infrastructure and its sea of new flats and office blocks are nearly all unoccupied, making it China's largest ghost city.
Another factor was China's fiscal recentralization reform of 1994, in which the central government raised its own revenue by taking back power from local governments to levy some major taxes. The move lowered local governments' revenues but left their financial responsibilities -- providing education, health care, subsistence allowances, and pensions -- unchanged. So local officials had to find other ways to generate money.
