When we shouldn’t tax bullshit
And when we should
People are sometimes dishonest and/or wrong, which is unfortunate. Luckily we have a way to combat this: bets! As the saying goes, a bet is a tax on bullshit. The theory goes that if we allowed more betting in our everyday lives (and maybe even institutionalized it with prediction markets) we would slowly trend towards a more honest and truth-seeking society.
Unequal money
I would like to push back against this idea a little bit.
The marginal value of money decreases as you get more of it. A hundred dollars might be a vitally important amount of money for a poor person, and not even noticeable for a rich person. So if you bet against a person with less money you are wagering less of your happiness than they are.
If they have health problems (and live in a country with bad healthcare) this bet increases their risk of death, which it doesn't for you. It seems to me that betting against someone who is poorer than you is morally dubious.
What if you think a poorer person is wrong and you think it's important to publicly signal so? Well, you still make a public bet, just without involving money. If you suspect your interlocutor isn't honest, the fact that you suggest a public bet gives them a status incentive to be honest.
If you think this isn't enough you can suggest that you put in a bit more money to compensate for the difference in wealth. This might not work if you yourself are too uncertain about the outcome, but in scenarios where you have a lot of confidence it might still be worth it in expectation (e.g. betting a $100 to $1 that the sun will rise tomorrow still seems like a good deal)
Another way is to bet with money, but give them the money once you win. However, you can only do this trick once, otherwise people might use this behavior to extract a constant stream of money from you. Alternatively, if you bet against a moderately poor person you might consider giving the profits to an extremely poor person.
Punishment for wrongthink
A bet is a tax on bullshit, but sometimes bullshit is necessary. Consider a closeted atheist living in a fundamentalist country where apostates are beheaded. I could extract a lot of value from their dishonesty by offering bets about various religious occurrences, which they'd have to take lest they out themselves. But this is cruel right?
And it's not just deceptive atheists. Say someone is poor and their only support network is the local church/religious community and/or they live in a country where apostates get beheaded. This person (unlike the atheist) might be an honest believer, but if the punishment for failing to self-deceive is ostracization or death, maybe it becomes cruel to consistently start bets with them. (This line of thinking can be extended to other scenarios where someone is under heavy pressure to think or talk a certain way.)
It’s important to note that these considerations cut both ways. If you, a non-rich person, can extract value from someone like a televangelist, I think it becomes not just prudentially-, but also morally important to take that opportunity.