They're not, but often, the wealthier the country, the more the difference in pay between men and women because women can simply get whatever job they're intere

They're not, but often, the wealthier the country, the more the difference in pay between men and women because women can simply get whatever job they're interested in without regard to the money. If you are in India or Russia, the difference between being a programmer vs local laborer is extreme, so anyone who can become a programmer (or similar high paying job for multi-national company) will. Thus, Russia and India have more female programmers (and similar) than the US.