Schedule

Group Discussion:

Even at Manifest - perhaps especially at Manifest - there are many folks who aren't sold on prediction markets, Let's have a group discussion about it.

Potential Objections:

Prices are not probabilities. Manski showed there is little theoretical basis for reading binary contract prices as event probabilities; prices get systematically toward 50-50, producing favorite-longshot bias.
Long-horizon markets select against the best forecasters. Skilled traders face high opportunity costs, so they have little incentive to bet on markets longer than a year without a very large edge.
The quoted price is often untradeable. Researchers attempting to trade battleground-race markets found zero sellers in some and bid-ask spreads upwards of 50% in others, making the prices cited by media phantom figures.
Resolution is the weakest link. A single holder of 25% of UMA voting power forced a $7M Polymarket contract to resolve "Yes" on a Ukraine minerals deal that never happened.
Manipulation is rational when the price moves the world. Election markets shape perceived candidate viability before voting begins, so a manipulator can lose money on the trade and be "non-truth seeking" - while still "profiting,"
Accuracy is not decision-relevance. A calibrated "will X happen" price carries no causal or conditional information, and the conditional markets that would actually inform decisions are thinner and harder to resolve than the headline ones.
Markets consume epistemics; they don't produce them. Prices aggregate journalism, polling, and expert analysis while rewarding traders for hoarding informational edge rather than sharing it.

These are just a few. Come argue for your own personal objections that you find most compelling.

You may find you aren't alone - yes, even here at Manifest.

(The session title doesn't represent my position; I only seek to facilitate the discussion.

Prediction market supporters are encouraged and welcome to join.)

Group Discussion:

Even at Manifest - perhaps especially at Manifest - there are many folks who aren't sold on prediction markets, Let's have a group discussion about it.

Potential Objections:

Prices are not probabilities. Manski showed there is little theoretical basis for reading binary contract prices as event probabilities; prices get systematically toward 50-50, producing favorite-longshot bias.
Long-horizon markets select against the best forecasters. Skilled traders face high opportunity costs, so they have little incentive to bet on markets longer than a year without a very large edge.
The quoted price is often untradeable. Researchers attempting to trade battleground-race markets found zero sellers in some and bid-ask spreads upwards of 50% in others, making the prices cited by media phantom figures.
Resolution is the weakest link. A single holder of 25% of UMA voting power forced a $7M Polymarket contract to resolve "Yes" on a Ukraine minerals deal that never happened.
Manipulation is rational when the price moves the world. Election markets shape perceived candidate viability before voting begins, so a manipulator can lose money on the trade and be "non-truth seeking" - while still "profiting,"
Accuracy is not decision-relevance. A calibrated "will X happen" price carries no causal or conditional information, and the conditional markets that would actually inform decisions are thinner and harder to resolve than the headline ones.
Markets consume epistemics; they don't produce them. Prices aggregate journalism, polling, and expert analysis while rewarding traders for hoarding informational edge rather than sharing it.

"I'm Anti-Prediction Markets - Here's Why" (Group Discussion)

"I'm Anti-Prediction Markets - Here's Why" (Group Discussion)