ne possibly explanation, for instance, is that countries with high gender inequality also tend to have high income/status inequality. So, only an elite class of people in those countries actually have access to higher education. There might be more functional gender equality among the elite class than in the general population. Or the elite class might educate their daughters as a mark of status. Or children of the elite might be strongly pressured to study high-earning disciplines like STEM.

Very true. Agreed completely.

Also, boys and men of these high income families are more likely to study abroad than girls and women.

People react differently to persecution. Those women might be fighting oppression by pursuing STEM careers. Sometimes, oppressed class simply fight back. For example: despite suffering severe persecuted, Jewish people managed to become prominent scientists. In fact, most prominent physicists are Jewish.

instead of asking "why aren't women choosing STEM?", maybe we should be asking "why are women choosing chemistry instead of engineering?" and "why do so many researchers exclude science and medicine from their studies of STEM?"

True. Women are also more likely to persue multidisciplinary STEM fields such as biomedical engineering, astrobiology, biomathematics etc.. But academics researching underrepresentation of women choose to ignore these fields. These fields are far more important than chemical engineering. Some even managed to convince public that biology is a soft science! Can you believe it? Soon...chemistry will also become a soft science!