A joke popular among disciplined officers patrolling the border tells of how some illegal immigrants botch their attempts to sneak into Hong Kong because of the SAR's deceptively rural look near the fence. Under the cover of darkness, the immigrants manage to climb over barbed wire and dodge border surveillance. Guided by the lights of gleaming tall buildings in the distance, they make their dash for prosperity, only to run into the cold embrace of mainland public security officers. For the bright buildings they think are symbols of prosperity are actually situated in socialist Shenzhen, not capitalistic Hong Kong. The joke is a satire on the rural character of the SAR's border areas vis-a-vis their equivalent on the Shenzhen side. Hong Kong's long-standing policy of preserving farmland and fish ponds along the border is an integral part of measures aimed at combating illegal immigration. Despite massive urbanisation of the New Territories over the past decades, there is no plan to turn the border areas into new centres of population growth. By contrast, in order to reap the full benefits of proximity to Hong Kong, the Shenzhen authorities decided to develop areas close to the SAR when it became a special economic zone in the late 1970s. That explains why the most built-up areas of Shenzhen are a narrow strip of land along the border. By proposing to develop Chung Ying Street in Shataukok, a village at the eastern end of the border, Cheng Yiu-tong, a member of the Commission on Strategic Development and a local deputy to the National People's Congress (NPC), is making yet another call for a rethink of Hong Kong's policy of not developing the border areas. In fact, the policy has been challenged from time to time over the years. For example, one proposal involved turning parts of the border areas into special industrial zones where mainland workers would come over to work during the day and return home to Shenzhen at night. The idea, championed by industrialists a few years before the handover when Hong Kong experienced a severe labour shortage, failed to materialise as officials were keen to maintain the integrity of the border. Literally meaning 'Sino-British Street', Chung Ying Street is bisected by the line of demarcation between Hong Kong and Shenzhen. Hong Kong law bars access to Shataukok, except by indigenous residents and visitors with a legitimate purpose. But the Shenzhen side of the village is not a closed area and has been developing rapidly like other parts of the special economic zone. Although Shenzhen also restricts access to Chung Ying Street, the rules are not as strict as Hong Kong's. The lax rules on the Shenzhen side have allowed Shataukok villagers to exploit its jurisdictional novelty into a tourist attraction. For mainland visitors, Chung Ying Street affords them a rare glimpse of 'Hong Kong', no matter that the mode of life there is a far cry from what most SAR residents actually experience. The visitors enjoy buying tax-free gold ornaments and electrical appliances on sale in shops on the Hong Kong side of the street. The novelty has even drawn Hong Kong visitors, even though they can get there only by making a long detour, by crossing to Shenzhen through other immigration checkpoints and then getting a visit permit from the Shenzhen authorities. In view of Chung Ying Street's popularity among mainland visitors, Mr Cheng has proposed to build a shopping complex on the Hong Kong side of the street and to relax strict access rules. The NPC deputy said fears of illegal immigrants sneaking through the village should no longer be a major concern because their number had dropped sharply and they had other ways of coming in. Mr Cheng has a point, but whether his proposal should be pursued and strict border rules relaxed is another matter. Despite Hong Kong's reunification with the mainland, the Basic Law provides that the SAR remains a separate Customs territory, both for people and goods. Any moves which might undermine the integrity of the border need to be balanced carefully against this overriding consideration. Mr Cheng also wants to develop a Chinese herb production and biochemical technology zone at the border. What he may want to bear in mind is that while cross-border co-operation should be encouraged, it should not necessarily mean locating joint ventures at, or close to, the border. The moment Hong Kong started to fudge its border, the international community may perceive that as a sign of Hong Kong becoming just another part of China. Besides, to facilitate border control and avoid congestion caused by cross-border traffic, there is a need for a buffer zone between the border and the built-up areas. The experience in Shenzhen of having built-up areas close to the border is that traffic congestion is aggravated by cross-border vehicles. Mr Cheng's proposals may be modest, but their implications are not.