A lot of readers interpret this paper as “women get paid less because they’re less productive.” Personally, I think the authors are trying to convey a subtler message.

• Why are fewer women on the street during rush hours? Many female drivers told me its because they need to pick up their kids, and/or other family members. Thus, we should not read “women prefer to not drive during rush hour” literally, and use it to justify lower pay. Rather, it is a phenomenon worth studying in the future, as the authors suggested. If our society has longer school day like other countries, better after school programs, and/or more affordable elderly care; and if these responsibilities are shared more equally between two partners, would there be just as many female drivers during rush hour?
• Speeding less = Lower productivity, which justify lower pay? Remember that speed limit is set for a reason — safety. Drivers who speed is earning more money at the risk of incurring more accidents.
• Less experience => Lower pay is a real concern for a lot of women. Many of my stay-at-home mom friends cautioned me against staying away from the work force for too long. In the future, I am planning on getting a certificate in AI/Machine learning during my maternity leave, to accumulate more human capital. But I am aware that not many women have the luxury of doing so; nor does it necessarily fit their career paths. So gender gap due to less experience might always exist. And this hidden cost of child bearing is one that many women should take into account when planning their family.