>"... One analysis of 11 rich countries estimates that the average mother spent 54 minutes a day caring for children in 1965 but 104 minutes in 2012. ..."

This is analysis is just hard to believe. Between reading books, preparing food, driving to activities -- a full-time parent spends probably 4-5 full hours, except when another parent takes over or there is a continuous split.

The interrupt costs are also very high (and affect negatively ability to work).