The mathematics of this seem sound. The ideological overhead ("cooperation is good"), however, seems wrong. The same outcome that the author achieves with pooling in a group can be achieved by an individual just splitting their wealth into N pools, and then playing the coin-toss individually with each of those N pools.

Also, I suspect an even better outcome for an individual would be achieved by essentially using the Kelly criterion, which means that you wager a certain fraction of year wealth on every coin-toss. The optimal fraction that should be wagered on each toss can be calculated with pretty basic math.

For the lefties: this doesn't mean that cooperation is bad, of course. It just means that the argument in the article can not be used in support of your ideology.