Observability, and common knowledge matter for what norms can be enforced.

That’s why it’s totally possible to have norms for masks that condition on whether your inside or outside—something that’s easy for everyone to observe and agree on. https://twitter.com/erezyoeli/status/1385282458984271881

(As evidenced by the fact that such a norm seems to work just fine, for instance, here in Germany.)

(See this review paper and Ted talk for evidence observability and common knowledge are key for sustaining norms.) https://www.google.com/url?q=https%3A%2F%2Fwww.dropbox.com%2Fs%2Fjysgcuc5oiq9ks9%2FHarnessing%2520Reciprocity%2520to%2520promote%2520cooperation%2520and%2520the%2520provisioning%2520of%2520public%2520goods.pdf&sa=D&sntz=1&usg=AFQjCNHLajR2-M8IPh0335drlEex_qcFWg https://www.ted.com/talks/erez_yoeli_how_to_motivate_people_to_do_good_for_others/up-next?language=en

(And see this thread for some experiments+discussion that builds on this same logic to explain why we have a hard time sustaining the norms that condition on impact, ala effective altruism.) https://twitter.com/moshe_hoffman/status/1315738384162197505