This chart published in Harvard Magazine has won my heart.
It is well executed in many ways. The chart illustrates a study of time spent by assistant and associate professors. It focuses specifically on time spent working versus time spent on household chores. One of the obvious questions of the study is whether female professors are disadvantaged when they have family obligations.
The general visual framework is the profile chart. Four segments of professors are arranged left to right from single with no children to married, with children and both parents working or single parent. The chart makes these points clear:
- Having children adds about 15-30 hours to time spent on household duties, per partner
- Household duties are not evenly split by gender, with the expected bias. (Of course, this observation must be carefully vetted. The men and women are not married to each other, even on the right side of the chart. But I presume the usual interpretation should hold.)
- Male professors with kids do spend more time on household chores than those without but not as much as female professors with kids
In the meantime, the amount of time spent working is about the same for all four segments, raising a side question: what other activities got displaced? The juxtaposition of the lines allows us to see that the displaced hours are almost 50 percent of the total time spent working! What did they do less of?
I especially like the explicit depiction and labeling of the "gender gap" (the orange vertical lines). Also, the use of median hours instead of average hours.
My one little complaint is that the designer forgot to tell us the hours are off a weekly basis (I'm guessing here). Just adding "per week" after "median hours" would have fixed this.
One simple chart cannot address all possible questions on such a complicated subject. I like the restraint the designer exercised in not saddling the chart with too many questions.
I will just mention one tricky statistical issue. Getting tenure and making babies are both activities that occur within some time window in a professor's life, if at all. So there is a survivorship bias. The professors who receive tenure drops out of the picture. If you are older, and still in the pool, you probably are less "accomplished" from the perspective of the tenure-granting process. The longer you stay in that pool, the more likely you will have gotten married and/or have children--thus, there is an age bias going from left to right, as well as a survivorship bias. This implies that the characteristics of the professors in the four groups are likely to be different not just on their marital and child-rearing statuses but also on age and probability of tenure.