accept that the choice of an event to mandate vaccination or not makes very little difference to the odds of getting covid

I don't disagree.

I assume if you require a covid vaccine you're also requiring a flu vaccine?

I mean, I'm not requiring anything. But I do think that events that decide to require covid vaccinations should generally also require flu vaccination, yes.

This doesn't sound right to me. Let's take a very simplified situation.

• Imagine there are several identical places where I'm considering buying a bunch of land and then building transit there to make it more valuable.
• The value of land if this option were removed is $V_1$
• The value of land after I build transit to it is $V_2$

I get all the land owners together and we have an auction, where I offer to buy from whichever owner gives me the best price, wouldn't you expect to end up with a price much closer to $V_1$ than $V_2$?

In a real scenario properties wouldn't be identical which makes an auction a poor fit and it wouldn't look exactly like this, but it doesn't seem that far off?

Now, you might say that $V_1$ is actually quite high, nearly or exactly as high as $V_2$ because these land owners could sell to someone else who also has a "buy land, build transit" approach. Then I agree there's no profit, but that's a standard result in economics: under perfect competition economic profits are zero.

I'm not trying to say that the possibility of increased density via transit has no effect on land values relative to today: I agree the possibility of transit raises land values. My claim is that it doesn't raise land values very much.

But it also sounds to me like you're giving a mistaken framework for how to value things where there are many different amounts they could be worth in the future? I would propose using expected value: value the land in proportion to how much it would be worth in all of these different potential futures, scaled by their probability.

I don't know -- when I used Linux on my main machine I was happy with how things looked and generally preferred sites and programs that fit in with the rest of the environment. And Linux users are disproportionately the kind of people who, if they don't like their system's default font, will pick something they prefer.

Smiling is communication. The information content of a message is inversely proportional to its probability. If you smile at strangers in places or situations where that's very unusual, you're communicating pretty strongly, and not necessarily what you intend to communicate.

For example, I live in a part of the world (Northeast US) where the culture is to leave strangers alone. You don't talk to them, smile at them, etc; everyone just does their own thing. If someone here smiled at me out of nowhere, my first reaction would be trying to figure out where I knew this person from, and I'd probably smile back to be polite. Then if they moved on and I really didn't know them I might wonder why they had smiled at me; were they flirting? Visiting from out of town and didn't know the customs? On drugs? Indicating support for something I'm signaling with my appearance or attire?

I can report that nearly half of the strangers will smile back, although often they'll look away as they do.

I'm not sure that's as positive as it sounds? The "look away" part seems to me like it's indicating discomfort, or that they're worried returning your smile will escalate the interaction.

The organizers considered A, B, and C, and chose B. An attendee asked why not C, and I wrote up my personal views on why I don't think C is a good choice.

(I was trying pretty hard not to get into the object level stuff here, but ok, let's go. On why I don't rank A very highly, I think vaccination, especially the initial series, is great at protecting the recipient from the severe effects of covid. In terms of protecting others, which is the main thing that matters if you're deciding whether to restrict some people from attending the event, I think someone who had covid three months ago is probably less of a risk to others than someone who was boosted nine months ago. Other people's vaccination status just isn't a very good proxy for how much risk they pose.)

At the current time, I think $C<A<B$. When conditions were different I thought $C<B<A$. I have a lot of trouble imagining a situation in which I wouldn't think $C<max(A,B)$.

A decision procedure where you eliminate $A$ and then decide between $B$ and $C$ even if you think $C<A$ or $B<A$ is a pretty bad one.

It's pretty clear that 1 is true. I think 2 is false, and therefore 3 is false.

In which case a group should not choose C, because A is better.

My overall point with this post is that groups should not be choosing C.

I don't understand the inclusion or discussion of B (which seemed to be the bulk of the post)

The bulk of the post is about my objections to C, though?

There's lots of land that could have transit built to it, but won't unless someone does. The two specific projects I gave as examples are unusual in that they are atypically good fits for transit expansion, but this general approach makes a lot of sense even if you give that up. And has lots of historical precedent.

This is a bit like saying no one would sell rural land cheaply to be used for a charter city because once the city is built that land would be really valuable, ignoring that there are many sites a potential charter city builder can choose among.