Prediction markets = A tool for quantifying the conventional wisdom

No GravatarEric Zitzewitz responded to Paul Krugman:

Almost all of the serious people who study or work with these markets are not in the “markets are magic” camp.

My work in this area (with Justin Wolfers usually and Andrew Leigh and Erik Snowberg occassionally) uses these markets as a way of quantifying the conventional wisdom.

This has more value than may be immediately apparent. It can help you get from “the market rose 0.25% in response to Obama’s Iowa victory” to “the market rose 0.25% in response to Obama’s Iowa victory, which raised his nomination probability by 20% and did not affect the Democrats odds of winning in November” to an estimate of how much more stocks will be worth under Obama than Edwards or Clinton.

In corporate settings, a market can help turn something that “everyone knows” into an objective fact that can then be acted upon. The best example is probably markets on whether software projects will be completed on time- if a market run among the project team members says that the launch will be 2 months late, it becomes harder for the project manager to insist that everything is on track.

Eric Zitzewitz
Assoc. Prof. of Econ
Dartmouth College

Thanks to Jason Ruspini for the link. Jason also posted a comment on Paul Krugman’-s post, and also on Felix Salmon’-s post.

Previous blog posts by Chris F. Masse:

  • NUCLEAR SCANDAL: HubDub allow their traders to bet on celebrities’ death.
  • APRIL FOOL’S DAY: This year, again, CNET makes fun of the wisdom of crowds.
  • Play-money prediction exchange HubDub is a phenomenal success.
  • BetFair Australia’s spin doctor tells all about their payments to the horse race industry.
  • Meet Jeffrey Ma (at right on the photo), the ProTrade co-founder, and whose gambling life is the basis of the upcoming movie, 21.