It is outrageous if a similarly-qualified woman would have a lot more trouble getting the $500k investment banker job. In that case, society is getting lower-quality investment bankers despite spending $500k/year on them.

Which is illogical. I will tell you my company would love to hire someone at a 30% discount.

Except when you consider that wages rise and fall in fields depending on the gender makeup of those positions [0].

[0] http://www.nytimes.com/2016/03/20/upshot/as-women-take-over-...

Consider this. I have a group of 100 people, 50 male and 50 female. Job x is available in industry y. Job x is highly sought after and all 50 men apply for it. Industry y is traditionally male dominated and for whatever reason, none of the 50 women have previously applied for the job. Through the magical powers of the internet, women are now suddenly interested in the field and not only do the 50 men apply for the job but the 50 women do also; doubling the applicant pool.

How will the employer react to the sudden surge in applications?

But that's not what the article is talking about, it's talking about male-dominated fields that were once female-dominated and vice versa.

One of the previously male-dominated field that the article mentions is computer programming. There is no other field in the article that has undergone such a fundamental shift from when women used to dominate the field. There were virtually no barriers to entry to the field back then either in the form of requiring a degree or societal norms ingrained from childhood.

Other fields mentioned either require longer hours or were simply more demanding. We can get into what are reasonable hours or demands in a separate conversation but all things equal, employers are going to pay more for someone who works longer and puts up with more demands.

For everything else, when you introduce half the working population to a field that they were once closed off to, wages are going to drop. I am not pretending that it's the only factor but a huge over supply of labor will cause wages to drop; all things equal.

Is there something about the male gender that makes one a better investment banker? If not, how do you explain why that is in the first place?

There's abundant evidence that women prefer to work fewer hours than men and working insane hours is (for better or worse) a requirement of investment banking.

Whether the preference for fewer hours is innate or learned I don't know.

Women flat out don't want to do it. Some do, but not many.

I flat out don't believe that.