Prognootling refers to a small-group or two-person decision made via a wager. It's based on the idea of decision markets, aka futarchy. In its simplest form, we make a single conditional prediction market: "if we take action A, will good thing G happen?". If the probability of G is high enough, we deem A to be a good idea. Importantly, we commit ahead of time to taking action A if and only if the market probability exceeds an agreed threshold. If we don't, because it doesn't, we void the market.

Warning: there are ways for that to be wrong! But we have case studies, pre-Manifold, of it working correctly -- things like the time @bethanysoule and I decided whether to risk destroying our car.

Here's an illustrative scenario:

Yesenia and Noah are partners who have a standing handshake agreement to buy mana from each other at face value. One day a stranger offers to sell them some magic beans. Yesenia thinks she and Noah should buy them and that a magic beanstalk will totally sprout. Noah says, "uh, no". They agree on a utility function over the possible worlds (wasted money, golden harps, angry giants), multiply everything out, and conclude that if the probability of a magic beanstalk is at least 20%, the beans are worth a shot. Pulling the 20% threshold out of their butts is fine too. Either way, they agree that if the probability of a magic beanstalk were ≥20% then it'd be worth a shot. If not, it wouldn't be. Yesenia and Noah have reduced their disagreement about buying magic beans to a disagreement about a probability. What now? Off to Manifold!

1. They create a market: "If we buy these magic beans, will we get a magic beanstalk?" 💹

2. The market price starts at 50%, implying magic beans, go!

3. Noah spends a trivial amount to drive the price down to 19% (🫘👎)

4. Yesenia puts in a big limit order for YES at 20% (🫘🚀)

5. Noah buys NO, eating as far into Yesenia's YES limit order as he dares

6. Maybe he ends up happily hedged: the price stays at 20%, they're buying the beans, but if the beanstalk fails to materialize, he'll be made whole

7. Or maybe he eats through Yesenia's YES limit order and puts up his own: NO at 19% (🫘👎 again)

8. Yesenia can now counter or not

9. The price tug-o-war continues until they're both happy 💪🔗💪

10. They do what the market dictates 🎉

Again, doing what the market dictates means that (a) if the price ends up below 20% then they don't buy the magic beans and the market resolves N/A and no money changes hands; and (b) if the market price ends up 20% or more then they do buy the magic beans. In that case they then wait to see if the beanstalk appears and resolve the market YES or NO accordingly.

If third parties show up and place bets, Yesenia and Noah shouldn't mind as long as they have their tug-o-war at 19 and 20%. If they let the price bounce up and down, that could create an arbitrage opportunity for third parties.

But what if Manifold is full of magic bean skeptics and the market price immediately plummets to 5% and Yesenia doesn't have the capital to buy the price up to 20%? Noah gets his way -- no magic beans -- with no mouth-money needed. One answer is to bite that bullet and say this only improves the situation. The market price is more accurate and Yesenia gets a better deal on her YES shares if she does move the price up. Maybe that's even more ROI-positive from her perspective than the beans! But if Yesenia and Noah don't like that, they can always make the market unlisted.

Markets exemplifying this protocol

1. https://manifold.markets/dreev/what-will-happen-if-cantor-goes-ice

(additional examples to be added here as we collect them)

Resolution Criteria

Point to examples in the comments. I'll review them and add them to the above list if I agree that they count. The market resolves to the number we've collected as of market close 6 months from now.

FAQ

1. Do instances in the past count?

No, starting today. But please point out any older instances you know of in the comments anyway!

2. Do they have to be on Manifold?

No, but it has to be on some platform that's enough like Manifold that you can click a link and confirm that it played out according to the protocol described here.