Link of the day: Installing air filters in classrooms has surprisingly large educational benefits
In 2015, Los Angeles suffered from the Aliso Canyon gas leak, where gas leaked out of a well near LA. The carbon footprint may have been larger than that of the Deepwater Horizon Leak. In reaction to the leak, many schools invested in air filters (for about $700 to $1000). This provided a very nice natural experiment. Michael Gilraine found in a working paper that these air filters have surprisingly large positive effects on the students’ performance. You may also be interested in this article about health and cognitive problems associated to air pollution.
Gelman himself took a look at the paper and was not impressed.
Without having dug deep, it really seems like the methodology doesn’t quite match the rhetoric.