Hong Kong's men are disappearing. The ratio of men to women has fallen from 1063 per thousand in 1993 (four years before the handover to China) to 912 men per thousand women today. They project that the ratio would plummet to 763:1000 by 2036, but surely there would be big changes before that gross imbalance were reached.
The number of unmarried young women has gone up dramatically. Hong Kong women are major players in Kay Hymowitz' "New Girl Order" that I wrote about yesterday. Single male numbers have gone up, too -- Hong Kong is a rich city for young singles. But the single women rate has gone up much faster than the bachelor rate. And Hong Kong men are much more likely to marry mainland women than Hong Kong women are likely to pair up with mainland men. This is ironic, since mainland China has a huge overhang of men compared to women. But Hong Kong women are much better educated and career oriented than mainland women, and less likely to be as subservient as mainland men normally want a wife to be.
The scariest number in Hong Kong demography is the fertility rate: 0.98 children per woman. Most industrialized countries are below the replacement rate of 2.1, but Hong Kong is the first (as far as I can tell) to fall below the one kid per woman threshold. No place can sustain a population pattern like that for long. The Hong Kong administrator wants to raise the fertility rate to 3 children per woman, which most people regard as wildly unrealistic.
The Hong Kong government offers no speculation as to where they men have gone. My guess is that the men have gone to the mainland. They are taking their world market savvy, honed in non-Communist Hong Kong, and are getting in on the ground floor of the booming post-Communist mainland economy. Odds are that those men will marry, but probably locally.