The sustained, long-term growth of Hong Kong and other cities in the Pearl River Delta depends on a co-ordinated strategy by the region's governments. By working together to put in place the necessary infrastructure and regulations, the best possible conditions for future development can hopefully be attained. The suggestions in the first-ever joint planning study by Hong Kong and Guangdong authorities are therefore welcome. As worthy as the recommendations may be, those in charge of the process must keep in mind that ultimately, the direction must be determined by market forces, not planners. There is nothing wrong with the ideas at the core of the study by Hong Kong's planning department and its Guangdong counterpart. Hong Kong, Macau and Guangdong should work more closely together, it rightly says. Efficient transport links between the three major city clusters - Guangzhou and Foshan , Hong Kong and Shenzhen, Macau and Zhuhai - should be built, as suggested. Using the San Francisco Bay area as a model gives a target to work towards. In putting forward such proposals, it must be remembered that Hong Kong, Shenzhen, Macau and Guangdong do not have the same governance rules. In Hong Kong, for example, the government is a regulator and its role as a developer is largely reduced to providing primary infrastructure. The mainland economic system is evolving towards a mix of markets and socialism, at different paces depending on the province and city involved. Laws and practices essential for the functioning of markets are not always in place. Guangdong is the nation's most economically-advanced province, but its government nonetheless maintains a considerably higher level of involvement in industrial planning than does Hong Kong's. The study determined Hong Kong and Shenzhen would make an ideal hub for financial and service industries because of the cities' expertise in finance, trade, technology and shipping. Such an assertion is all well and good, but should not evolve into a development straitjacket. However good the planners' blueprints are, businesses may or may not respond to their well-intentioned designs. The designation of areas for certain industries does not necessarily mean those industries will be happy to set up there. As essential is ensuring that the infrastructure that is put in place is coupled with appropriate policies to take advantage of what has been built. Take, for example, the western corridor that connects Tuen Mun to Futian in Shenzhen. It remains underused due to licensing restrictions on vehicles able to cross the border. At a macro level, immigration and customs controls are also adding to the time taken for goods and people to move around the delta. The study outlines the need for rail links to be built between the three population hubs so that travel times are no more than 60 minutes. This would already be largely attainable were these checkpoints to be streamlined or abandoned. Planners have to have the vision to think about what could happen in the region. But planning should not come at the expense of people being able to make business decisions. Markets must be allowed to hold sway. Policy bottlenecks are often a bigger obstacle to economic development than inadequate physical infrastructure. Looking back, no one could have foreseen 30 years ago that the delta would develop into China's economic powerhouse. The development is not the result of planning, but that of a policy change that allowed Hong Kong manufacturers' demand for cheap land and labour to be met by the region's abundant supply of both.