There might not be gender-specific pay scales, but that doesn't mean that companies don't unconsciously discriminate against women. When someone is offered a salary, what the company basically says is, "how little can we offer this person and still get them to work for us?" In the room, they're just looking at the individual, but Forbes magazine quoted a study saying that men will be offered more than women 69% of the time for the same job. In addition to this, when new employees ask for more money in salary negotiations, men are successful 15% of the time, whereas women are successful just 4% of the time. Men are also more likely to negotiate for a better salary (48% compared to 32%). People aren't rewarded for their work based on competence, they are rewarded based on perceived competence (especially in initial hiring). And all sort of unconscious biases make their way into that decision. That's why, for example, tall men earn more than short men on average and better looking people are less likely to be found guilty by a jury. And women are likely to be offered less than men for the same job.
