[warbaker]

The real with prediction markets problem is that people can make bets, then alter outcomes to match those bets. This is a well-known issue in sports betting (e.g. taking a fall), and I don't see how we're going to prevent it for things that matter a whole lot more than sports.

[ericzundel]

Also, a bet in these markets can be used to alter outcomes. That problem is caused by journalists reporting on market activity. It is treated (or percieved by readers) as if it reflects popular sentiment. Not only is it possible, it's actually relatively cheap to do things like corner the market, which in some cases is a lot less expensive than, say, a national TV ad campaign or running a scientific poll. Link to an older article: https://insights.som.yale.edu/insights/dont-trust-the-politi...