It's funny you say that, in Australia, women in engineering and other STEM fields are highly saught after. To the point of affirmative action in hiring, scholarships for women for education in those fields etc. In Australia at least, women who complete a masters in engineering are basically guaranteed employment after their degree, while the market is much more competetive for men.
The thing is, the women with the talents and skills just don't want to study engineering. Instead, these women choose other fields such as medicine, law and accountancy.
No economist worth their salt would acknowledge the '23c pay-gap' as being legitimate. If that were so, there would be 0 reason to hire males for menial jobs, since female labour would be significantly cheaper. Comparisons of lifetime earnings are deeply flawed.
While we're on it, that 1/5 statistic is also bogus, and it makes me mad to see such a serious issue as sexual harassment be used to sell t-shirts. Sexual harassment is a serious problem, inflating it with bogus statistics does nothing to help victims of harassment, nor does it help solve the issue. Inflated statistics lead to ineffective policies and overreaction. With an issue as important as sexual assault, it's important to address it thoroughly and accurately.