There is no policy on matching population growth with natural resources, a senior planning official has said. Acting Secretary for Planning and Lands Patrick Lau Lai-chiu said it was difficult to predict how big a population pressure Hong Kong could withstand in the coming decade. According to the Census and Statistics Department's latest project, he said the average annual population growth would drop from two per cent in the past decade to 1.2 per cent in the next. 'How big a population size the SAR can support depends largely on the usable natural resources available. But it is hard to predict changes in the amount of usable natural resources over the next five or 10 years. Actually, the amount of usable resources is determined by many complex factors such as economic growth, technology advancement and people's behaviour and habits. For example, no planning experts could have predicted a few decades ago that the amount of food would sharply increase due to the development of genetic engineering.' Mr Lau said for this reason the Government had not attempted to assess the amount of usable natural resources available or on that basis formulate a policy to restrict the population. But he was confident there would not be great pressure on land supply in the next decade. The Government had, on the basis of various population scenarios, mapped out long-term planning strategies and assessed their respective implications on natural resources and the environment, Mr Lau said. Of the population growth, 30 per cent would arise from natural growth, that is, births minus deaths, with 70 per cent from net population inflow, which refers to arrivals minus departures. Mr Lau said the definition and compilation method of demographic data would be reviewed as there had been significant changes in residence patterns and the mobility of the population in recent years.