Could vaccinating cattle get more girls into high school?

That's the intriguing prospect suggested by a new study of Kenyan cattle herding families in the journal Science Advances. But even more significant than the actual results of the study is the fact the researchers would even think to investigate whether there's a link between cattle vaccination rates and girls' high school attendance.

That kind of thinking is not typical, says study co-author Thomas Marsh, a professor of economics at Washington State University. More often, the scientists who study methods for improving agriculture in poor countries tend to focus entirely on the method itself — whether and why does it work. Less common is to check the broader impact of the intervention: Does it reduce poverty, open up economic opportunity and generally improve lives — which after all, is the whole reason to introduce better methods.

A case in point, adds Marsh, is the research on cattle vaccinations. Raising cattle and other livestock is the primary source of income for millions of poor people across eastern and southern Africa. And prior research has established that when herders vaccinate their cows against, for instance, the tick-borne disease East Coast fever — the leading killer of calves in the region — they get more milk from their herd. But Marsh and his collaborators wanted to know more: What was the impact of the increased milk production on herders' incomes. And how did they spend any extra money?

"Could we find evidence that it was making a real difference?" " asks Marsh.

So the researchers conducted detailed surveys of about 500 households that raise livestock in Kenya, then did a statistical analysis. As expected, the greater the share of its herd that a household vaccinated, the greater the amount of milk produced and the greater the overall household income.

And how did the families spend their increased income?

One of the most important boosts was to the education of their kids. Specifically for each additional cow vaccinated (at acost of $6.37 per animal), the family ended up spending about $4 more per school semester on their children's education.

It wasn't the family boys who got the benefit. The study's finding suggests that it was primarily the daughters. Specifically, the researchers found that each increase of 10 percent in the share of a family's cattle that was vaccinated was associated with a 0.8 percent increase in the likelihood their daughters attended secondary school.

By contrast, an increase in vaccination had no impact on the likelihood that boys attended school.

But there was a cattle/son connection. The higher the rate of cattle deaths a family suffered, the lower the likelihood their sons were in either primary or secondary school. Cattle death, however, had no impact on girls' attendance rates.

How to explain these differences? Marsh posits that when it comes to spending on education many families may give priority to their sons over their daughters. So if they're only making a little money, they spend it on sending sons to school. This would be why a son's education could be vulnerable to major shocks to the family's income like a sudden rise in cattle deaths.

It's only once the family does particularly well – by, for instance, vaccinating more of their cows and boosting their milk production — that they use spend the resulting extra income on schooling for their girls.

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