This question is plagued with uncertainty.
The White House isn't sure. The US Public thinks it was probably a lab leak, but Wikipedia thinks it probably wasn't. Rootclaim is pretty sure it was a lab leak, but Manifold is pretty sure that they lost the $100k debate about it being a lab leak. However, Manifold also thinks there's a 70%-80% chance it was a lab leak nonetheless, but that we probably won't know one way or another for many years. But Manifold also thinks there is a 24% chance that the big market about it will resolve controversially. Metaculus also has mixed opinions.
I don't know who to believe!
Except, perhaps, Zvi Mowshowitz.
Zvi paid very close attention to Covid throughout the entire pandemic and did a lot of fantastic blogging on it. He regularly puts numbers on exactly this sort of thing. He's also active on Manifold and has a good track record. If Zvi said a probability, I'd take that probability seriously.
So what does Zvi believe?
In May 2021, he said 40%.
At this point, I think I am somewhat below Nate Silver’s 60% odds that the virus escaped from the lab, and put myself at about 40%, but I haven’t looked carefully and this probability is weakly held. I’m sharing it because it’s important to share probabilities even when they’re weakly held. The question of whether we’ll ever prove what happened, or the official story will conclude a lab leak, is very different from the question of the actual origin, so there’s no pure way to evaluate such predictions, but it seems important to give a number even with my uncertainty.
In June 2021, he said 55%:
Thus, I’m not changing my probability all that much. I’m now at something like 55%, up from 40%, now that I see more about how this all went down, but it could still easily have gone down either way.
In October 2022, he said:
Did Covid-19 leak from a lab? We will probably never know.
Well that all seems very reasonable, but I still want to know what number he'd put on it now. Is it still 55%? I haven't been able to find any more recent opinions from him on the subject.
If he doesn't publicly state a probability after market creation and before the end of 2024, this will resolve to the last option accordingly.
If he does publicly state a probability, this market resolves to the option containing that probability. Please don't bother Zvi to give a probability just because of this market, I think it's better if he gives a number in his own time as new evidence comes out.
Note that Zvi betting on a market about COVID origins, including this one, wouldn't count as him stating a probability. It needs to be a direct statement.
I may make minor updates to these rules within the spirit of the question, so feel free to offer any suggestions.
Related questions
An hours-long detailed debate is so much better than not having one, but the result is still highly correlated with the skills and knowledge and strategies of the two debaters, so in a sense it is only one data point unless you actually go over the arguments and facts and check everything. Which I am not going to be doing.
(I mean, I could of course be hired to do so, but I advise you strongly not to do that.)
The practical takeaway is that, without any desire to wade into the question of who is right about any particular details or overall, it seems like everyone (even when not trolling) is acting too confident based on what they think about the component arguments, including Scott’s 90% zoonosis.
I do not see any good arguments that a lab leak or zoonosis couldn’t both cause similar pandemics, everyone is merely arguing over which caused the Covid-19 pandemic in particular. And I claim that this fact is much more important than whether Covid-19 in particular was a lab leak.
Zvi knows about the debate. In his recent Medical Roundup on Jan 16, he says:
If you want to engage with the debate, well, good news, it seems there is an 18 hour recorded debate, a third of which is published, six figures at stake on the outcome and a prediction market on the outcome.
Daniel Filan: One thing I'd like to emphasize: I think this is the best debate I have seen in my life. Object level informative, and worth wondering how to emulate. I genuinely wish political debates had this format.
I still am not about to watch hours of that.
The prior should not be low:
William Eden: The prior on lab leaks happening IS NOT LOW. It does NOT require extraordinary evidence for a lab leak being a source of an outbreak. This is always a reasonable hypothesis and must be investigated
Ian Birrell: New study reports 309 lab acquired infections and 16 pathogen lab escapes between 2000 and 2021
If we have almost one confirmed lab leak per year, and given the other circumstances, it would almost be surprising if Covid-19 wasn’t a lab leak.
Was Covid a lab leak? We don’t know. At this point it seems more likely than not.
@kenakofer Thanks for linking! Definitely should shift this market upwards a bit. Or maybe this is bullish for him not wanting to put a number on it other than saying he's currently over 50%?
Once you think the number is substantial, it does not much matter if your probability of the lab leak is 30%, 50%, 70% or 90%. They should drive most of the same changes in policy, and the same reflections. They won’t.
Imagine how we and you would have reacted if we had known, back in February 2020, that this virus had escaped from a lab. Then ask which parts of that reaction you would endorse on reflection, and which you do would not. Then act accordingly.
All great points, and I should hope everyone agrees that we should be massively more careful with this kind of research regardless of if Covid was specifically a lab leak.
But still, I do want to know! Hopefully he's more specific sometime soon.