I promised you the answer to the calculation that the Harvard medical school people got so terribly wrong, but because of some news I saw in the NY Times today (https:\/\/www.nytimes.com\/2020\/06\/01\/health\/masks-surgical-N95-coronavirus.html), I wanted to do a quick post updating my post: <\/p>\n\n\n\n
garycornell.com\/2020\/04\/21\/multiplication-of-probabilities-or-what-to-do-when-you-have-to-go-shopping <\/p>\n\n\n\n
In that post, I first guessed about what the various probabilities might be about how much safer various precautions made you. Then I used “multiplication of probabilities” to come up with a guestimate of what doing three different things together would help by.<\/p>\n\n\n\n
That NY Times article I just mentioned had some actual numbers on how much your risk is lowered by various activities: “Standing more than three feet away cuts the risk of transmission to 3 percent from 13 percent, the analysis found. Use of masks reduces the odds of infection to 3 percent from 17 percent, and eye protection to 6 percent from 16 percent” <\/p>\n\n\n\n Anyway, let\u2019s assume these numbers are true and that it is reasonable to assume these are “independent events”, which I think they are. Then, if you take all three precautions and other people wear a mask,<\/em> you reduce your risk of catching Covid-19 to:<\/p>\n\n\n\n Added: Tracked down the article the NY Times was referring to:<\/p>\n\n\n\n https:\/\/www.thelancet.com\/pdfs\/journals\/lancet\/PIIS0140-6736(20)31142-9.pdf<\/a><\/p>\n\n\n\n (See table 2.)<\/p>\n\n\n\n Added(2): The importance of other people wearing a mask<\/em> repeatedly!<\/p>\n","protected":false},"excerpt":{"rendered":" I promised you the answer to the calculation that the Harvard medical school people got so terribly wrong, but because of some news I saw in the NY Times today (https:\/\/www.nytimes.com\/2020\/06\/01\/health\/masks-surgical-N95-coronavirus.html), I wanted to do a quick post updating my post: garycornell.com\/2020\/04\/21\/multiplication-of-probabilities-or-what-to-do-when-you-have-to-go-shopping In that post, I first guessed about what the various probabilities might be … Continue reading “Updating the post how to be safe – independent events – some good news”<\/span><\/a><\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"jetpack_post_was_ever_published":false,"_jetpack_newsletter_access":"","_jetpack_dont_email_post_to_subs":false,"_jetpack_newsletter_tier_id":0,"_jetpack_memberships_contains_paywalled_content":false,"_jetpack_memberships_contains_paid_content":false,"footnotes":""},"categories":[6],"tags":[],"class_list":["post-262","post","type-post","status-publish","format-standard","hentry","category-the-pandemic"],"jetpack_sharing_enabled":true,"jetpack_featured_media_url":"","_links":{"self":[{"href":"https:\/\/garycornell.com\/wp-json\/wp\/v2\/posts\/262","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/garycornell.com\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/garycornell.com\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/garycornell.com\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/garycornell.com\/wp-json\/wp\/v2\/comments?post=262"}],"version-history":[{"count":10,"href":"https:\/\/garycornell.com\/wp-json\/wp\/v2\/posts\/262\/revisions"}],"predecessor-version":[{"id":274,"href":"https:\/\/garycornell.com\/wp-json\/wp\/v2\/posts\/262\/revisions\/274"}],"wp:attachment":[{"href":"https:\/\/garycornell.com\/wp-json\/wp\/v2\/media?parent=262"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/garycornell.com\/wp-json\/wp\/v2\/categories?post=262"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/garycornell.com\/wp-json\/wp\/v2\/tags?post=262"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}
First off let\u2019s be clear, they mean you and every other person wearing a mask<\/em>! If other people don\u2019t wear a mask, all bets are off.<\/p>\n\n\n\n
.03*03*.06 = 0.000054 (!)<\/p>\n\n\n\n
which, to give you a sense of perspective, is less than the chance of you dying if you drive 5000 miles. And since this number is presumably only the chance of catching Covid 19, I’m now willing to bet that if I use all three methods, and my neighbors wear a mask <\/em>that I am safe. In any case, if this calculation is true, then this is a very low risk-thankfully!<\/p>\n\n\n\n