Hong Kong's People Ethnic Identity

The Public Opinion Programme of the University of Hong Kong (HKU POP) has just released the results of the latest survey on Hong Kong's people ethnic identity. The press release can be found here, and the sample question wordings of the survey can be found here.
HKU POP has been doing similar surveys ever since Hong Kong was handed over to PRC in 1997. One chart, in particular, calls for attention.

Strength of "Chinese citizen" identity (per poll, by age group) (8/1997 - 6/2012)
(Click for a larger image)

This chart by age group shows a sharp drop in how strong young people (18-29 yrs) identify themselves as "Chinese citizen." Robert Chung, Director of HKU POP, observed,

Our latest survey shows that in terms of absolute rating, people’s identification with ‘Hong Kong citizens’ has dropped back a bit compared to 6 months ago, but their identification with ‘Chinese citizens’ has dropped to a 13-year low since the end of 1999. Indepth analysis shows that the rating of those under 30 years of age continues to drop since mid-2009, and plunges to just over 5 points in the past 6 months. This warrants special attention. Moreover, if we use a dichotomy of ‘Hong Kong citizens’ versus ‘Chinese citizens’ to measure Hong Kong people’s ethnic identity, the proportion of people identifying themselves as ‘Hong Kong citizens’ outnumbers that of ‘Chinese citizens’ both in their narrow and broad senses, by about 28 to 38 percentage points. For those under 30 years of age, the gap widens to 60 to 72 percentage points. For the overall sample, the percentages of those identifying themselves as ‘Hong Kong citizens’ both in its narrow and broad senses (including ‘Hong Kong citizens’ or ‘Chinese Hong Kong citizens’) have reached record high since the 1997 handover. Moreover, if we use ‘identity indices’ ranging between 0 and 100 to measure the strengths of people’s identities (the higher the index, the stronger the identity), Hong Kong people’s feeling is the strongest as ‘Hong Kong citizens’, followed by ‘members of the Chinese race’, then ‘Asians’, ‘Chinese citizens’, ‘global citizens’, and finally ‘citizens of the PRC’. All in all, Hong Kong people feel strongest as ‘Hong Kong citizens’, then followed by a number of cultural identities. The feeling of being ‘citizens of the PRC’ is the weakest among all identities tested. As for the reasons behind the ups and downs of these figures, we will leave it to our readers to form their own judgment using the detailed records displayed in our ‘Opinion Daily’.

This also stirs up quite some voices on the internet. Wan Chin suggested adding three further questions to the survey:

1. If CCP or PRC falls, will you identify yourself as a Chinese citizen?
2. If ROC regains control over mainland China, will you identify yourself as a Chinese citizen?
3. If people from mainland China are willing to be colonized by Hong Kong after a referendum, will you identify yourself as a Hong Kong citizen or a China citizen?

It remains to see further reactions from different people in Hong Kong and China.