1. What are the demand side issues? Age gap has been mentioned as a problem of men wanting younger women, but is this a one-way street? Do women also prefer older men (at least until they’ve become “older singles”), and if so, will encouraging the guys to seek close-in-age or older women do much if a bias against close-in-age or younger men persists?
2. It has been mentioned that Hassidim have more close-in-age shidduchim. How else does their system differ? Do more men work? Do they spend a shorter time learning in the late teens/early twenties? Is there the same expectation that in-laws finance long-term learning? How do these differences affect the men’s ability to start dating sooner?
(Hypothetically, if Hassidic men start dating at 19-20, but also start working and don’t expect their in-laws to finance long-term learning, then there will be a smaller age gap, but there will also be different expectations about what the kallah’s family brings to the table financially and about the relative status of learners vs. earners. In fact, the smaller age gap will be an effect of these other considerations, rather than an independent factor affecting their shidduch outcomes, so simply looking at their culture of smaller age gaps without also considering the other components of the system won’t help much.
Again, I’m a ger and an outsider to this phenomenom, so I really don’t know the ins and out of the Litvish vs. Hassidic systems and whether the hypothetical in #2 reflects reality.)