I don't know if this personal contemplation of the unfair wage gap is useful for any other reader. I just wanted to find out what I think about the "wage gap" and its relation to discrimination.

What we know is that there are, for example, pay gaps between ethnic groups. It's often hard to say why they exist exactly but certainly discrimination is one reason; either customers or employers discriminate against an ethnic group. Discrimination can happen in one area or field while in another area or field the same group can be favored.

If the group is discriminated against, they find it harder to find jobs and thus they can be paid less (in other words, their supply is greater).

In the end, an efficient market should erase the discrimination if it's not backed up by economic reasons: employers who irrationally favor one group over another are outcompeted by those employers who base their business on an economic rationale. Thus an employer can discriminate against one group if his customers consider the discrimination to be OK and are willing to pay extra for the favored group. Otherwise he must employ the more productive person nevermind the group he or she belongs to. Or face bankruptcy.

But this is an ongoing process and it's never "ready". There will always be stereotypes that cause discrimination. If one is erased many new can be born. That's because we must rely on stereotypes in our thinking. It's impossible to see a person as an individual - and often it's impossible to even try because we don't have the resources (like time) to do it.

In practice, this means that in some jobs employers are willing to pay more to women (and in some other jobs to men) not because they are more productive but because "that's the way it's always been" or some other (perhaps) irrational reason that makes them favor women in recruiting. A man can get recruited only if he is willing to accept a lower salary.

Where I live this is happening (or used to happen, at least) in certain grocery stores and in restaurants.

I know this is not the "gender wage gap" people are usually talking about. But it's the unfair part of it and it does exist. And it exists for both men and women.