To solve long term betting, we could simply not require the mana to be paid up front. That way, you don’t lose out on investment returns before the market resolves.

But how can you be sure the person you are betting against will pay out in 5 years? You can’t.

However, you can get close, by matching against people you trust!

Enter peer bets

• For any market, propose a peer bet, at a probability and amount of mana
• Anyone can offer to take your bet
  • For any subset of the amount of mana you offered
• The original proposer will determine if they trust you and accept or reject
• The fee is the typical prob * (1-prob) * shares * 0.07, but split in half for each side to pay
  • Fees are paid upfront. You pay it when you propose the peer bet (or propose to match the peer bet), and get it back if cancelled.
  • E.g. 1M mana at 50% is 2M shares, so the total fee is 0.5 * (1-0.5) * 2M * 0.07 = 0.035 * 1M = 35k. As one side of the bet, you would pay half, or 17.5k.
• When the market resolves, we automatically deduct mana from the loser, if they have enough in their balance
  • Otherwise, the loser’s account enters a “must pay debt” mode, where there’s a big permanent banner on their screen to pay up
  • If they don’t pay after a week, they get added to the Wall Of Shame, a page for people who didn’t pay their debts, which shows their name and email address (probably)
  • Otherwise, nothing happens. Manifold is not responsible for paying people back. You are taking on this risk when you make a peer bet.

I think these will be the main way to trade on long term markets (>1 year away). And they will be really useful at giving accurate probabilities on questions that otherwise would be hard to price. E.g. Covid lab leak, AGI, etc.

Lastly, I think peer bets are great for publicity. Each peer bet can have it’s own page which you can share that shows the two bettors and their bet amount. We had the idea once before with “Challenge bets”, but I think this new mechanism supercharges them.

UX

• Add a tab to every market called “Peer bets”, like the Trades tab
  • Where you can propose peer bets and see excecuted ones
• A new question type which only allows peer bets
• A page to display the Peer Bet