Divorce rates have shown steady trends related to developing nations, while female worker participation is related to lower rates of abuse. Bargaining power = love.

Maybe. Or maybe it's not love. Relationships endure (or don't) for a lot of reasons, one of which is the usefulness each partner sees in the other in times when love isn't holding up. A woman with a job is useful in a very objective sense; her income makes finances easier, and money troubles are almost as universal as our DNA.