Nov 30, 2021
Noah Smith has a good summary of the Omicron evidence here, including a lot of quotes from experts. But experts say a lot of stuff like “well, it could be bad, but we can’t be sure”, plus sometimes they disagree. This is the kind of situation where prediction markets are useful, so let’s look at them.
R0 is a measure of how quickly a disease spreads under certain ideal conditions. The original Wuhan strain was probably around 2.5, and the Delta variant was probably around 5. So if this number is higher than 5, it’s more transmissible than Delta. The community prediction is 7.31, so Metaculus predicts it will be significantly more transmissible than Delta.
Metaculus didn’t want to wade in to precise lethality statistics, so they just asked for a yes-or-no answer on whether it would be deadlier than Delta. Forecasters say there’s a 34% chance it will be.
The specific resolution criteria is if at least 3 of the first 4 studies find a statistically significant difference “favoring” Omicron. That feels pretty strict to me, so you should think of this as the probability that it will be really noticeably deadlier than Delta.