Fresh air is better for learning

How do you get children to learn better at school? You can change the curriculum, the teachers, class size, or the administrators. You can provide incentives to the teachers, children or their parents (unfortunately, you cannot change the parents). You can bus children to other schools. You can add more equipment to the classroom. All this may be effective to some extend, and in some cases not. That is a major part of what the Economics of Education field is about, and there is obviously still a lot to do, given how the latest PISA results show dramatic differences across countries.

Tess Stafford adds another piece to the puzzle. As a Texas school district went through a renovation project for all its schools that involved improving indoor air quality for most of the schools, and those projects were staggered over several years, it became possible to see how students test scores have changed before and after the renovation. They improved, and significantly. Stafford even claims that it has a stronger impact than reducing class size. So if you have poorly ventilated and moldy schools, you know what to do.