The Bechdel Test has been used in these last few years as an index of the degree … something.
Basically to pass the Bechdel test, a story (originally a movie, but it works for any narrative) must feature two female character, both with a name, that share a dialogue in which they do not talk about a man.
It’s been pointed out that the Bechdel test – that originally started as a joke in a satirical comic strip – is a useful tool to spot gender inequality, but beyond that, it’s very much a matter of hand-waving.
A story can pass the Bechdel and still be a pile of drivel, while a story can fail it spectacularly and still be a good, solid, fun and significant story.
Case in point?
Debbie does Dallas passes the Bechdel, Fistful of Dollars does not.