[makomk]

They probably can't actually know the answer any better than that. Think for a moment about this statement from the article: "There is not a single documented Covid infection anywhere in the world from casual outdoor interactions, such as walking past someone on a street or eating at a nearby table." That's probably true, but how would you even find those infections? There's no record of who walked past who on the street, no way to contract trace every stranger that passes by an infected person, and generally countries don't even try. So the fact that this form of infection hasn't been documented to happen says very little when it's so much harder to detect than indoor transmission. Ultimately, where you draw the numerical line is going to mostly be a matter of personal judgement, and no matter what choice the CDC make the New York Times will always be able to find experts who back a different conclusion.

(Also, the word "casual" is doing a lot of work in that sentence. There absolutely have been documented examples of outdoor transmission via, for example, people going for walks together or chatting with each other outside. So if people think that this means all outdoor interaction is safe, as the article seems to be inviting them to do, this could cause some real problems.)

[spfzero]

In your first paragraph, you say there's no way to contact trace outdoors, and in the second you say there are documented cases of it happening.

There are ways to predict your chances of getting infected from someone outdoors. You back-trace from known cases, identify the people they have interacted with, and from those that later contracted Covid, you note whether the contact was indoors or outdoors. There is plenty of data to do that with.

[makomk]

The instances of outdoor infection that have been documented aren't just random strangers passing each other on the street or sitting near each other - as I recall they involved people who knew each other, which obviously makes contact tracing easier. Also, one of the ones I know of was in New Zealand during the period where every case was headline news and aggressively investigated, and the other was in China which similarly had very few cases that were very aggressively traced. This does not say good things about how well countries with more cases are detecting outdoor transmission.

[michaelt]

> That's probably true, but how would you even find those infections?

Well, you could look at the infection rates among people who attended large outdoor gatherings during the pandemic in spite of warnings - like Trump rally attendees or BLM protesters.

Or you could look at infection rates for people who have a tractable list of possible exposures - interview only people who live alone and work from home, and see if people who only shop for food have a lower infection rate than people who shop for food and also golf once a week.

Or you could run an experiment - get some infected people, have them cough at petri dishes inside and outside, with and without masks, and at different distances.