Shenzhen, PRC, March 2010. Shenzhen had a population of about 30,000 in 1979; thirty years later, that figure exceeded 8.6 million, only 2.1 million of whom had an official hukou (local registration). The city's growth, after its designation as a special economic zone, eventually culminated in the highest per capita income, the most active export route, and the highest share of Ph.D.s among all of China's cities. "...it was Shenzhen that set the tone and stage as it became the experimental ground for FDI, joint ventures, land tendering, contractual employment, and the blurring of urban and rural distinctions through migration. When these successful experiments became transplantable and replicable in other areas, Shenzhen began to lose its special status. ... Shenzhen has grown out of its instant-city stage to become a huge industrial city confronting new challenges that threaten its continued prosperity." Xiangming Chen and Tomas de' Medici (2010). "The 'Instant City' Coming of Age: Production of Spaces in China's Shenzhen Special Economic Zone." Urban Geography 31(8), 1141-1147, quote from p. 1145, 1146.