I can't say that I am very impressed with this study. It seems to be a very basic calculation looking at the number of available toilets and the amount of time a woman would need to walk to find an available facility. They seem to have then just calculated the risks of being attacked whilst walking around for that much time.

Presumably the same analysis could be done of women waiting at bus stops, walking to friends, etc. It does not look like they have specifically taken account of anything about the use of sanitation, the risks to women of using the facilities, whether more attacks happen at night or in isolated places etc.

This one is from PLOS ONE, so it is freely accessible for everyone to read.

Background

Sexual violence is a major public health issue, affecting 35% of women worldwide. Major risk factors for sexual assault include inadequate indoor sanitation and the need to travel to outdoor toilet facilities. We estimated how increasing the number of toilets in an urban township (Khayelitsha, South Africa) might reduce both economic costs and the incidence and social burden of sexual assault.
Methods

We developed a mathematical model that links risk of sexual assault to the number of sanitation facilities and the time a woman must spend walking to a toilet. We defined a composite societal cost function, comprising both the burden of sexual assault and the costs of installing and maintaining public chemical toilets. By expressing total social costs as a function of the number of available toilets, we were able to identify an optimal (i.e., cost-minimizing) social investment in toilet facilities.

Findings

There are currently an estimated 5600 toilets in Khayelitsha. This results in 635 sexual assaults and US$40 million in combined social costs each year. Increasing the number of toilets to 11300 would minimize total costs ($35 million) and reduce sexual assaults to 446. Higher toilet installation and maintenance costs would be more than offset by lower sexual assault costs. Probabilistic sensitivity analysis shows that the optimal number of toilets exceeds the original allocation of toilets in the township in over 80% of the 5000 iterations of the model.
Interpretation

Improving access to sanitation facilities in urban settlements will simultaneously reduce the incidence of sexual assaults and overall cost to society. Since our analysis ignores the many additional health benefits of improving sanitation in resource-constrained urban areas (e.g., potential reductions in waterborne infectious diseases), the optimal number of toilets identified here should be interpreted as conservative.

The full study is here: journals.plos.org/plosone/article?id=10....journal.pone.0122244


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Title and authors:
Reducing Sexual Violence by Increasing the Supply of Toilets in Khayelitsha, South Africa: A Mathematical Model
Gregg S. Gonsalves , Edward H. Kaplan, A. David Paltiel