Increasingly, babies born in Hong Kong have mainland mothers. According to the Census and Statistics Department, 43 per cent of the 78,822 babies - almost 34,000 - delivered here last year were to mainland mothers. Only about 10 per cent of those mothers had Hong Kong husbands.
Those are incredible figures, considering that in 2001 only 620 babies were born to mainland women here. And the department estimates the numbers will continue to rise, reaching 40,500 this year, 45,500 next year and 49,500 in 2012.
Since Hong Kong women have one of the world's lowest birth rates - well below replacement level - it is good that mainland women are giving birth here, since their children will have the right of abode in Hong Kong.
The trouble, from the government's standpoint, is that there are too many unknowns. It is not known whether and when the babies will return to Hong Kong. One government survey of 11,643 parents suggests that the majority plan to send their children back to Hong Kong between the ages of three and 11.
That means there will be a large pool of school-age children coming to Hong Kong, who will have the right to free education.
Secretary for Education Michael Suen Ming-yeung has said that it is hard to estimate the education demand from these families as the government cannot keep track of them once they leave.