1. If SARS-CoV-2 originated in a non-laboratory zoonotic transmission, then the geographic location of the initial outbreak would be drawn from a distribution which is approximately uniformly distributed over China (population-weighted); whereas if it originated in a laboratory, the geographic location is drawn from the commuting region of a lab studying that class of viruses, of which there is currently only one. Wuhan has <1% of the population of China, so this is (order of magnitude) a 100:1 update.
This is an assumption.
While it might be comparatively correct, I’m not sure about the magnitude. Under the circumstances, perhaps we should consider the possibility that there is something we don’t know about Wuhan that makes it more likely.
3. There have been publicly reported laboratory escapes of SARS twice before in Beijing, so we know this class of virus is difficult to contain in a laboratory setting.
This is an assumption.
While it might be comparatively correct, I’m not sure about the magnitude. Under the circumstances, perhaps we should consider the possibility that there is something we don’t know about Wuhan that makes it more likely.
That’s nice to know.