Ok, this will be the last thing I say on this tired topic, because it increasingly feels like preaching Paganism to Jesuits. The Shenzhen article is quite clear on the topic of commuting: "According to the Hong Kong General Chamber of Commerce, in 2002, 7,200 Hong Kong residents commuted daily to Shenzhen for work, and 2,200 students from Shenzhen commuted to school in Hong Kong. Though neighbouring each other, daily commuters still need to pass through customs and immigration  checkpoints, as travel between the SEZ and the Hong Kong Special Administrative Region (SAR) is restricted." It provides handy sources. The year was around when Forstall did his "study." 7,200 people reverse-commuting to SZ and 2,200 students going from SZ to HK on thei student visa hardly fill the 20% quota. The 7,200 usually are HK businessmen who visit their SZ factories (or their mistresses, parked in SZ apartment buildings.) There is no such thing as increased integration, and you should stay away from speculations. In any case, when the study was done, there was no SZ-HK commuting except for a handful of students, and there is none today. Forstall was patently wrong and ignorant when he bunched HK an SZ together for his study. People who copy him perpetuate his ignorance. HK and SZ did not fulfill one of  Forstall's own core criteria, namely massive commuting to the metro core, and it doesn't today. According to the HK treaty, nothing will change for 50 years after the hand-over. Forstall will have to wait some 40 years. Acknowledging the fact that there are people who believe that the world is flat, I rest my case.