There are a number of reasons why. Since China opened its doors in 1979, hundreds of thousands of Hong Kong men have been spending time at work over the border. Many of these men are earning salaries that, by Hong Kong standards, would be modest, making it difficult to raise a family. But the same income can readily support a wife and children in mainland China, where prices are dramatically lower. But fear of migration from China is great.
Many men leave their wives and children in China, and visit on the weekends or when business allows.
By contrast, if the bride was a resident of any other country, they could come to Hong Kong to live and work the day after marriage. Hong Kong's unusual policy hit a roadblock when the territory's highest court struck it down as unconstitutional early last year. But the government expressed alarm, and last June, Beijing overturned the ruling. A government campaign aimed at swaying public opinion against the court's ruling even included a calculation of how much it would cost to process the migrant's sewage if they all started using toilets in Hong Kong instead of mainland China. As a result, Hong Kong's missing children and their other close family members enter the territory through a slow and corrupt quota system that allows only 150 to cross the border each day.