Great idea! Makes me think, it would be interesting to see a political prediction market where the winnings go to your preferred candidate in the race. Not sure about if that would have a positive impact, but would be cool to study.

Edit: Just read your post and see that you discuss this haha

It seems like there is a lot of value in creating something that feels legitimate. Ideally more than just a niche group of EA/Rationalist folk would be interested in participating, and I don't think a "the feds would never know" argument would be convincing for a big audience. Thanks for sharing those examples though!

Oh wow, that's cool! Do you know how Hedgehog invests the play money?

Your last idea is a lot like a company giving bonuses to internal forecasters, seems promising. If prediction markets prove themselves worthy, maybe an EA organization will eventually decide it's worth it to regularly sponsor forecasting tournaments for global priorities work.  I'm excited to see where the space goes.

That entirely depends on the return on the bank’s investment, right? I have no idea what that could be in practice. If it were similar to the stock market, say 8% annually, then I think that would be very attractive to forecasters. Being right on a poll where 50% of respondents were also right would be like doubling what you expect to earn from stocks. But obviously that’s risky investing, so probably not feasible. Or if you were already a big bank, you could afford such risk, and make it worthwhile for winners. Was that what you were thinking?

Yeah it definitely takes time to do it right. But even if you personally do not have the time, starting the group first and focusing on finding people who do have the time could accelerate growth.