During the semester, treatments such as the provision of information on career prospects, average earnings, and grade distributions were provided to women in the treatment group. A nudging message was also sent to female students in the treatment group with a midterm grade above the median. Additionally, half of the treated female students were invited to attend mentoring activities throughout the semester.Few eligible female students (around 5%) took up the mentoring, so that doesn't explain the effects, which were that:
The treatment effect of interventions on female students with grades above the median is substantial. The treatments increase the probability of these female students majoring in economics by 5.41 – 6.27 percentage points. The effects are even larger for freshmen and sophomores among these high-performing female students, who are 11.2 – 12.6 percentage points more likely to declare economics as their major.To summarise, there was no treatment effect for below-median-grade female students, in terms of whether they went on to major in economics. The effect was entirely concentrated among above-median-grade female students. Interestingly, the effect of the intervention was actually negative for male students, which Li explains:
Conversely, the information treatment appears to reduce male students’ likelihood of declaring economics as their major by 2.67 percentage points. The effect is larger (−5 percentage points) among male students in the lower classes (i.e., freshmen and sophomores). Because male students in the treated group received information about careers in the economics profession as well as the grade distribution information with no nudges, the negative effect is likely attributable to their reaction to the grade information... students were overly optimistic about their grade performance upon entering the class. The overconfidence is particularly pronounced among male students.Overconfident male students obviously get the message that they aren't nearly as good at economics as they thought, when given more information about how the rest of the class is performing, and respond by being less likely to take an economics major. Unsurprisingly, this effect was concentrated among male students below the median grade (and the effect disappeared once Li controlled for students' GPA). On the other hand, female students (at least, those above the median grade) respond to the information by being more likely to take an economics major.
The results are interesting. However, I was more interested that prior to the intervention the information on grade distribution was not available to students. At Waikato, until we shifted to Moodle this year, students in economics papers could previously see detailed information on the grade distributions for each assessment (Moodle doesn't have this functionality, but for the tests and exam I routinely provide the mean, median, top mark, and pass rate to students, so at least there is some information). Encouraging top students in the introductory economics class to enrol in an economics major also seems like a no-brainer, and something that most schools would already routinely do.
So, in spite of the large and statistically significant effects in this study, it seems to me that the results are not generalisable to other settings because the intervention is so routine. However, if your university isn't already doing these things, then now is a good time to start!