Is this an argument against consequentialism or population ethics?
"A(G)I could radically change X" is a way weaker claim than "working on A(G)I is the best way to tackle X". You only defend the former here.
The section on forecasting quantities is really a special case of estimating any unknown quantity X given a prior and data when X has a true (but unknown) value different from the prior. You should expect your updates to be roughly monotonic from your prior value to the true value as data accumulates.
For example, if X is vaccine effectiveness of an unusually effective vaccine then the expected value of your prior for X is going to be too small. As studies accumulate, they should all point to the true value of X (up to errors/biases/etc) and your posterior mean should also move towards the true value.
An important difference here is foresight vs hindsight. At any particular time, you expect your future posterior mean of X to be your current posterior mean of X. However, once you know what your final posterior mean of X to be (approximately the true value) then updates up to that point look .
Appendix: maths proving the above for a simple case.
Great post, thank you. I hadn't considered the anti-synergy of treatment and vaccination explicitly before.
How much weight to put on the vaccine risks you mention in the following sentence seems very important to whether to fund anti-virals or not: "Treatment of the cases that happen later is either useful as a mitigation measure to slightly reduce impact, or a backup plan in case we don’t manage to make vaccines.".
At the start of this pandemic, most people thought vaccines might be very far off or impossible. I'm not sure how much to update based on exceeding expectations and ongoing with to shorten timelines. However, we seem to be quite good at testing therepeautics which seem to need less customising (hence easier production), especially when the side effects profile is well understood (eg the RECOVERY trial). While not an anti-viral, dexamethasone has probably saved a lot of lives. I don't know enough biology/medicine to be able to distribution how much we need to separate different classes of drugs.