Isn't this (and career choice) the explaination for the gap the other direction for the other cities? I guess I'm not seeing how this is different. Do you have some numbers showing what you're explaining (sometimes easier for me to see it that way).
Obviously other factors, such as the availability of high-paying, non-degree-requiring jobs in male-dominated industries (ex. oilfield work) might obfuscate other trends in some cities, but I'd expect young women to increasingly earn more than young men across the country if they continue to outpace them in educational achievement.
For example, I know a woman who has two masters degrees but doesn't really work. She is about 35 and has spent most of her life in school, focusing psychology. Even if she had focused more on working in the field of psychology than just serially earning degrees, she would still be at the lower end of pay due to those jobs paying less than STEM jobs.
This anecdotal experience seems to be backed up by the BLS study that also acknowledges that more women are graduating college but that choice of career/subject has not seen that translate into higher pay. That's why I was wondering what is driving the inverse scenario in those cities. Is it that women are choosing STEM there? Are policies in place that promote women from not working low paying jobs (ie makes it more attractive to be a homemaker instead of pay for childcare while working hospitality etc). Or is it cultural, like lower birth rates or more male caretakers?
That said, the prevalence (or lack thereof) of high-paying industries with gender-imbalances could also contribute to the scenario described by the article. For example, a notable lack of STEM jobs or a local economy based around healthcare could both lead to a city's young women earning more than its young men.