When you are narrow-minded, mean-spirited and ignorant, you end up being one of those 100 or so people rallying in Tsim Sha Tsui against mainland visitors. Yeah, yeah, I know. I have heard all the arguments about how mainland visitors don't benefit the average Hongkonger, only those in property, retail and high-end services. They push up housing costs, pricing locals out of the property market. On the last point, you see something similar in London, New York, Singapore, Vancouver among other major world cities; that is, foreign buyers going into the local property market driven by the tide of central-bank-induced liquidity and low borrowing costs during the financial crisis. That is the kind of foreign or outsiders' buying you would expect to see in such an economic environment. The government's anti-property- speculation measures, whether you agree with them or not, have cooled such buying. But the main point is a moral one. If you believe in one China and that we are all Chinese citizens, then mainland visitors have every right to be here. It is also very hard to deny that, without the mainland, Hong Kong would have fared much worse during the Asian financial crisis, the Sars outbreak and the global financial crisis. We don't know how lucky we have been when it comes to unification. Not only has the handover been bloodless and peaceful, it has become a pillar of our economic foundation. Most other peoples and countries have had to pay a far heavier price. By one estimate, German reunification has cost that nation two trillion euros over 20 years. Between two and three million Vietnamese died during the Vietnam war that led to the country's unification. If and when North Korea collapses, is there any doubt the South will have to foot the bill, including integrating North Koreans into normal society? But these are countries and so are not comparable to a city like Hong Kong, you say. Well, the size of our population and economy is bigger than many full states around the world. Sure, we fret and complain about our streets and public facilities being crowded by visitors. But we could have a lot worse to whine about than Prada-wearing mainlanders.