The Undercover Economist

Snips, Snails, and Puppy Dog Tails

There’s finally proof that boys do ruin schools for girls.

My colleague at the Financial Times, Isabel Berwick, recently mourned the closure of her fondly remembered all-girls’ school and regretted “a slow societal shift away from girls-only schools and colleges.” As the father of two young daughters, I am paying attention.

Yet “slow” is the operative word. Girls’ schools are clinging on tenaciously in the public sector here in Britain: More girls go to single-sex schools than boys. In inner London, parental preferences for girls’ schools are particularly pronounced. The Guardian has reported that more than half of inner-London girls attend girls’ schools, and just over a quarter of boys attend boys’ schools. The result, of course, is that the mixed schools contain a disproportionate number of boys.

Parents make these choices because of a widely held belief that girls thrive in single-sex environments. But is that true? And what are the implications for the girls left surrounded by emotionally retarded adolescent males?

We are in the realm of so-called “peer effects” here, and they are notoriously hard to measure. Girls’ schools produce good academic results, but that could be because particular types of parents favor such schools, because those schools have a strong historical record, or because of selection. I was lucky enough to go to a state-funded, single-sex, selective school in a prosperous neighborhood. My classmates did well in their exams, but there is an embarrassingly large range of explanations as to why.

A new working paper from economists Victor Lavy of Hebrew University and Analía Schlosser of Princeton attempts to unpick the peer effects associated with gender, using data on nearly half a million students passing through Israel’s school system in the 1990s. They compared consecutive year groups passing through the same school, figuring that if one year’s group was 55 percent boys and the next year’s was 55 percent girls, that difference was very likely to be random and thus susceptible to meaningful number crunching.

Their answer chimes perfectly with the conventional wisdom: Boys benefit from being in a classroom with girls, but girls do not benefit from being in a classroom with boys. What is interesting about Lavy and Schlosser’s work is that it uses survey data provided by the children to work out what is causing the effects. The survey questions ask, for example, about violence in school, respect for teachers, classroom distractions, and relations among students.

Boys pollute the educational system, it seems, for a number of unmysterious reasons: They wear down teachers, disrupt classes, and ruin the atmosphere for everyone. And more boys are worse than fewer boys, not because they egg each other on but simply because more of them can cause more trouble in total.

It is all rather troubling, especially for the parents of little angels like my daughters. Evidently, it is impossible to satisfy the—apparently justified—parental demand to educate girls in single-sex schools and boys in mixed classes. (Not for the first time in my life, I conclude that the world doesn’t have enough girls in it.)

Researchers from the University of London’s Institute of Education have asked a related question, comparing mixed schools with single-sex schools (from the 1970s, when nonselective single-sex schools were more plentiful) rather than the varying gender balance within mixed schools. Their conclusions, published last year, were subtly different. They found that boys disrupt mixed classrooms, but found that boys did not do any worse if locked up in a single-sex school.

A social planner might thus conclude that all education should be single-sex. The difficulty is to combine this perspective with the principle of parental choice. I have the answer: a congestion-charge-style tax on parents who insist on polluting girls’ education with their testosterone-fuelled little monsters. The money could go toward hiring extra teachers—and riot police.