Hong Kong people can't deny the fact that Hong Kong isn't a
country. It is a Special Administrative Region of the
People's Republic of China. Its sovereignty
was transferred from United Kingdom to the PRC in 1997.
It's merely a movement of people within PRC (mainland to hong
kong and hong kong to mainland) and the nett change in population
of PRC (hong kong + mainland) due to this movement is zero.
In Singapore, the influx and outflux of people have resulted in
a nett change of population which isn't 0.
what is the impact of the HK 7 million population to the 1.3
billion in China, nett change means nothing. but what impact does
35000 pragnant women from mainland China has on the HK population?
what has the influx of tourists from mainland China has on HK? ever
heard of the locust? 
Statistics mean little....the fact is that their workforce is
shrinking, ours is not?