According to a NZ social scientist, there really is a shortage of men. Not only is the number of "Kiwi men in their relationship-forming years" much lower than their female equivalent - remember that the number includes men whom right-thinking women shouldn't touch with a barge pole (really ugly, unpleasant and/or stupid men), so the true number of possible mates for women in the 20-49 age group would be even more depressingly small. The idea is supported by the fact that I had to import my own mate from England.
The same article says that the situation is reversed in Denmark and Germany (and I would think China also falls into this category). The answer for women who don't want to stay single, and are reluctant to date men who are either very young or very much older, is clear - emigration.