A small overall disparity in gender ratio can be magnified into a large disparity in the dating population when you bear in mind that most people are paired up at any given moment. So take NYC's overall gender ratio (53% female, 47% male). If you assume 80% of people are in a relationship at any given instant, the actively single pool is actually 1.5 females per 1 male.
Women basically have zero leverage in the Manhattan dating scene, which means that it really is difficult to bring up things like kids, because most men here seem to think of kids as something that they'll get around to in their 40's if ever. Hence an article on egg freezing.*
*) Which I think is great--I think we need more "home grown" kids in the U.S. and if egg freezing gives people a way to do that, then great.
"The switchover from extra men to extra women starts at 35-39 for most big East Coast cities, but doesn't hit New York until 40-44"
If you break the population down into age groups (e.g. 0-10, 10-20, etc.) most younger groups have more men than women. Combine this with the fact that younger women tend to pair up with older men, and you get more unattached men in the younger groups (but more unattached women in the older groups).
The idea of freezing your eggs is still way too cost prohibitive for most women. This is unfortunate because it leaves only the "Sheryl Sandberg"s of world- wealthy and educated to take advantage of this opportunity.
That's not really typical.
The first time I met my now-wife (24), she said in no uncertain terms she didn't want kids. After two years of dating, kids suddenly became super important to her and panic started to set in about possibly not being able to have them.
On a per-capita basis (not per date, as casual dating may be more common), I'd guess that many (>60%, to put a number on it) of those in the dating market have at least some notion of a 5+ year future in potential dates.
My friends and I have generally looked for partners, not flings. A great long term match can be really worthwhile.
Those who look for flings date more. Most men who date are looking for flings. Thus, it becomes more likely that most who date are looking for flings.
See Jaynes's book "Probability Theory: The Logic of Science"
Most dates don't turn into anything serious, but I doubt most men who bother to date are looking for a "fling", your definition of "date" may just be overbroad.
Is that really the case? I mean if your intention of dating is to meet someone that may eventually turn into a lifelong partner, knowing if their stance on children is congruent with your own definitely seems like something you'd want to hash out pretty darn early.