So, in order to show that this is not specific to gender bias, I am asking you for a negotiation tactic whose rates of success and reception do not have a correlation with gender. If you cannot provide this then I will assume your claim is sourced out of your behind, which has even less clout than the scientists you express chagrin for (at least their stuff has been peer reviewed).
Assuming the one thing that I'd be willing to give at least A BIT OF credence to, that is in the gender-related sphere, that women more commonly have personality traits that make them worse at negotiating, I still don't see why we should try to fix that on the employer's side. Educate the women to negotiate instead, from a young age. Giving rewards to those who don't deserve them will lead to sloppiness and bad quality work, and the outrage of those who deserve them.
Sounds to me like "it has to be correlated to gender" was a quick solution to get some quick stats published.
Now I realize it's part of human nature to try and get as much as possible for as little as possible, but this takes it way too far.
You must be really daft if can you look at a bunch of stats like "women are paid 30% less than men" and then tell yourself "YES! this is a problem that I completely understand, I understand everything about this and what these people say is exactly what happens in the real world, we have to fix this".
What the hell does "as assertive as men" even mean. Is it some caricature of a man stomping his boss' desk to establish dominance? You're either assertive naturally or you're not, this applies to men or women. Fakes are easily spotted and ignored. Socially withdrawn/inept people or autistic people constantly draw the short straws when negotiating because there's no chance for them to be even close to remotely assertive even though in a STUDYYYYY the "scientists" could claim that "they were as assertive as others" just because they tried (unsuccessfully — a detail so easy to omit/ignore). You don't just go "ok now I'm going to be ASSERTIVE" and suddenly have everyone go your way, if you haven't developed that ability since childhood (or at least for a damn while), at which point you're using it by default.
Jfc, we live too relaxed lives, we have no problems so we invent some.