Whether a society chooses its marriage institutions to be polygynous, strictly monogamous, or tolerant of serial monogamy is rational and predicatable, and has much to do with the social and political economy of the day.
An African Paradox: Why Poor Women Earn More Than Their Husbands, And The Power And Politics Behind It
Data from Kenya shows that contrary to expectation, the likelihood that a woman earns more relative to her husband decreases, rather than increases, with her education and wealth