But that doesn't take into account responsibility or actual job done at all. Organisations only have a limited number of job titles and at higher levels people

But that doesn't take into account responsibility or actual job done at all. Organisations only have a limited number of job titles and at higher levels people are not as expendable. They do their own job. The only thing that does seem to explain a gap---but a much smaller gap---is that men are more likely to negotiate their salaries.