I noticed your point, but unless you can bring authoritative proof that the numbers have changed, using any numbers other than those in the Avi Chai study is pure speculation.
As I pointed out, the numbers are growing, so it would be pure speculation to say that they stopped growing.
“In an article on the subject, Yonason Rosenblum assumes 4% as well”
With all due respect to an excellent journalist, he is making an “assumption” as you pointed out. I see no source for this assumption.
As a respected journalist, he is privy to studies which we are not.
“On point 3, you would sacrifice the many girls who don’t have commitment issues etc. for those who do”
I’m not sacrificing anybody, I pointing out that the age gap is not the hurdle to the vast majority of older singles.
Even had you been correct, you’d be sacrificing the rest.
“On points 4 and 5, we seem to agree that it’s a bigger issue than either of us can decide (I’m not sure why you concede this on point 4 but not on point 5)”
Anything that will lead to net LESS people married doesn’t need Daas Torah to reject it, common sense is sufficient.
So you think that your common sense is better than 70 R”Y?
No. We already determined that these 70 R”Ys said nothing of the sort. They only encouraged boys to “consider” close in age matches. No chiddush there, any Rav etc in his right mind long before NASI would advise a boy not to reject a potential Shidduch just because she is “only” one year younger.
They didn’t say it’s okay to go out with similar age; nobody ever thought it wasn’t, so they didn’t need to. They encourage closer aged shidduchim.
If girls follow NASI’s directive to wait a year or two before dating, she will only have 2 or 3 years left.
To the best of my knowledge, you’ve totally misconstrued NASI’s directive. I never saw anyone encourage the girls to wait.