[lvturner]

Around 90% of the population of Hong Kong is wearing a mask right now. Despite the proximity to China, it's use as a transit hub and it's densely packed population - there are only 115 cases there.

While it's far from conclusive, I'd suggest this as valid evidence that the use of masks is helpful in reducing the spread of the virus.

[hef19898]

We simply don't have the data to back that up. And unless you are a domain expert, you wouldn't be able to reliably come to that conclusion even if we had.

[samatman]

We know that the sum total of what Hong Kong is doing is effective: rates of all infectious diseases in Hong Kong have dropped precipitously since emergency measures were put in place.

[lvturner]

I didn't state a conclusion, I stated that it was inconclusive evidence towards a hypothesis. Perhaps I wasn't clear enough.