It works the same basic way in the US.

There's the "etc." proposals too, going from the simple to the complicated -- including (amongst other things) the UM program requiring payment for an additional empty seat; or a sort of paid babysitter+seat program, etc.

The question would then arise if such "proposals" effectively price out the UM program from existence or transform it into being just a more exclusive, smaller program. Effectively size-ing down the UM programs by having it incorporate more (at additional expense) doesn't necessarily strike me as absurd although it will price a good number out of the market.

Also, this current UM policy may cause offence to some female pax as well -- particularly those who don't want UMs seated next to them. (Could the female pax protest in such situations? Sure, but most won't say anything for concern not to offend the child or to avoid any kind of verbal disagreement with crew.)

The absurdity of this whole situation is the presumption that (in the absence of such a policy) an UM would probably be seated next to male pedophiles on planes who will act on their perversions in flight against a previously unknown child on a plane with dozens upon dozens of others around to potentially witness or intervene. Applying BA-logic in conjunction with an understanding of real patterns of sexual molestation of children, minors shouldn't be seated next to any male passenger with whom they've previously spent more than 12 hours -- including their fathers and siblings.

Personally, I don't much care what BA does in this regard as long as BA's somewhat absurd practice doesn't cause inconvenience, discomfort, or unease to the people BA is more explicitly "prejudiced against" in these circumstances.

I would have liked an answer to that, especially as I'm curious how far BA is going to go in factoring in other akin risks and/or other passenger-related concerns (including but not limited to minors not traveling as part of the UM program) into their seating shuffle.