That's the part that bothers me. There is certainly a difference between estimating and knowing, even for Yale. I hope herd immunity will happen, but the fact is the world has never had to deal with anything like this before, given the global population and numbers of people that travel internationally.
That is why I am so adamant about refusing to accept the idea of herd immunity at 70% or any other percent. I don't see how anyone, including experts in the field, can do much more than guess. Of course I understand they're doing far more than just randomly deciding on a number, but that is not enough for me. I just hope they're guessing right.
Until it actually happens, I also don't see how anyone, including bkkguy, will succeed in convincing me otherwise. Then again, I don't know why anyone gives a damn about what I do or don't believe. I think the challenge really is not convincing me. I think the challenge is trying to overcome my stubbornness . . .