I agree that most of the bets here are accurate indications of probability; most are in the range of 20-1000 dollars, and also there is a culture of honesty that seems like it would prevent offering a bet that didn’t reflect someone’s probability of an event while representing that it did.
The most common case I see where betting odds and probability don’t match is with really small values.
It seems to be encouraged here to spontaneously do friendly betting in person. From my experience, this usually involves pretty small values (0-10 dollars) paid in cash. If I won a small bet like that I might buy a bag of chips, or something, but if I won twice as much I wouldn’t buy two bags of chips, and it probably wouldn’t be worth the effort to save it, so I would mostly just forget..
Another time this comes up is when people bet with fairly high odds ratios, for example $100 to $1. This ends up with pretty low winnings on the $1 side because the alternative is the $100 being way higher, less of a casual amount to bet. A lot of times this might as well be $100 to $0. the median hourly wage is like $17 (in the US) so it’s not even worth 4 minutes of time to get the $1 into your account. what you mostly win is pride.
I also have seen some cases on here of people discussing really big bets, with amounts in the ten thousands/higher, and assuming that the betting odds will still correspond directly to probability.
Mostly I’m trying to say that it seems pretty automatic here to equate between betting odds and probability, and really there are some very common circumstances where this is not the case. (in the spirit of https://www.lesswrong.com/posts/zhRgcBopkR5maBcau/always-know-where-your-abstractions-break)