A national comparison can be close to a natural experiment at times.
https://twitter.com/ianmSC/status/1470458665367109634?s=20
https://roundingtheearth.substack.com/p/the-chloroquine-wars-part-xxii
https://covidreason.substack.com/p/bangladesh-implodes
https://unherd.com/2022/02/were-masks-a-waste-of-time/