Now here's an idea. It occurs to me the the 46 million annual mainland visitors to Hong Kong must be responsible for generating a substantial proportion of the SAR's 6.4 million tons of waste swamping our overburdened landfills each year. So why not introduce a new policy: anyone who wants to visit Hong Kong has to take a 20 kg bag of rubbish back across the border with them when they leave. This would remove nearly a million tons from the local waste stream, significantly extending the life of our landfills.
For most people, the impact of this flood of visitors is largely negative - overcrowding; luxury goods stores forcing out affordable local shops and restaurants and pushing up rents, causing a general rise in prices - so this way we could ensure that every visitor makes at least one positive contribution to our welfare. And if it discouraged them from coming, well, only big landlords and luxury goods retailers would be greatly saddened.