MM: Omicron Variant

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 sounds like a job for prediction markets!

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.

Forecasters predict that Omicron will be more than half of US coronavirus cases by mid-March.

Of people who don’t think it will reach majority by March, it looks like about 15% think it will take longer, and another 35% think it will never be the dominant variant in the US. This could be because we successfully contain it (really?), because it’s not actually that bad and can’t outcompete Delta, or because some other even worse variant takes over before Omicron gets the chance.

All of this is implicitly another vote in favor of it being more transmissible than (and so moving faster than, and spreading further than) Delta.