Thornton and Oster, did a randomized controlled trial about the relationship between menstruation and attendance of girls in school in southern Nepal. Their finding is surprising: only about a third of a
day per year is missed due to girls’ period. The allocation of menstrual cups to girls has no effect on scores. Girls not allocated menstrual cups in the initial randomization were 2.6 percentage points less likely to be in school on days they were menstruating. This falls well below the 10-20% estimates made by policy makers.
Researchers randomly selected half of the girls in our sample and provided them with a menstruation cup to replace the cloths they had been using. They compared the increase in attendance rates on period days for girls with and without this improved sanitary protection and found no impact: both groups missed slightly more school on days with their period.
Does this mean that sanitary-related intervention is not worthwhile? They say No!
It is important to note that this does not imply that there are no benefits to better sanitary products. Girls in the study were very happy to have the menstrual cup: it limited the amount of time they spent doing laundry, and the majority of girls used the menstrual cup regularly and would recommend it to their friends. The bottom line is while policies to provide better sanitary products in the developing world may have positive value, we should not expect them to impact schooling.
Here is a related paper by the same authors on peer effects on menstrual cup take-up.
We estimate the role of peer effects in technology adoption using data from a randomized distribution of menstrual cups in Nepal. Using individual randomization, we estimate causal effects of peer exposure on adoption. We find strong evidence of peer effects: two months after distribution, one additional friend with access to the menstrual cup increases usage by 18.6 percentage points. Using the fact that we observe both trial and usage of the product over time, we examine the mechanisms driving peer effects. Our results suggest that successful uses by peers are more important than peer unsuccessful usage attempts. In addition, we argue that peers matter because individuals learn how to use the technology from their friends, but that peers do not a effect an individual's desire to use or attempt to use.