Robust, the prediction markets are the best mechanism for aggregating information. Thus, companies should use them for assessing strategy and hedging risks.

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Via Emile Servan-Schreiber of NewsFutures, John Auters in the Financial Times.

[…] This leads to [Justin Wolfers]&#8216- claim that [prediction markets] are the best way to aggregate information. This is true of any given amount of information. Take three economists and make them trade out a market over their predictions for next month&#8217-s inflation number, he suggests, and they will arrive at a more accurate prediction than a poll of the same three economists. In a market, those with stronger conviction (or inside information) can express that conviction- those less confident will not be willing to stake money. […]

Prediction markets remain subject to the same weaknesses as other markets. The principle of &#8220-garbage in, garbage out&#8221- [*] applies. If there is only poor information to aggregate, they will be as wrong as everyone else. […]

It would make sense to incorporate these odds when making investments. […]

Excellent.

(I don&#8217-t get his micro slam against the wisdom of crowds. Anyway.)

[*] As explained in the prediction market explainer published on the frontpage of Midas Oracle.

A historical Robin Hanson fanboy cant believe his hero signed Bobs ill-informed and unwise petition.

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Hal Finney:

My concern is that the small stakes limit of $2,000, the limits on who can operate markets, and the limitations on the scope of markets, will lead to spotty coverage which will preclude a robust evaluation of the merits of prediction markets in general. After all, we have intrade.com already which provides spotty coverage of a number of issues – how much more will this add?

Maybe &#8220-gambling can save science&#8220-, but I don&#8217-t see how these steps would show it.

Proof that you can be &#8220-high IQ&#8221- and still lack judgment (in small ways).

P.S.: Over that the micro slam above, I have the highest esteem and respect for Robin Hanson &#8212-a prediction market pioneer.

STEVE LEVITTS FREAKONOMICS HIJACKED BY HACKER – FAMOUS ECONOMICS BLOG TEMPORARILY DEFACED – ANTI-SPORTS BETTING BILE VOICED

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Freakonomics, the famous blog on economics, is powered by WordPress, which is known [*] to have grave security vulnerabilities. Yesterday, a dangerous hacker managed to get access to their blogging software, and published an opinion on the regulation of prediction markets, which represents the total opposite of what Steve Levitt believes in. No doubt the hacker (who signed as &#8220-The Australopithecus&#8220-) will get caught by the Police. No doubt Steve Levitt will get out of his torpor soon and re-establish the truth. We will then give airtime to Steve Levitt&#8217-s arguments, on Midas Oracle. We&#8217-re with you, doctor Levitt.

[*] I know that for a fact. Midas Oracle was hijacked yesterday by a dangerous hacker who signed as &#8220-The Barbecue&#8221-. I&#8217-m not responsible for what he said.

ABC 20/20 – A good (but servile) explainer on the wisdom of crowds and the prediction markets

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ABC 20/20 featuring InTrade – (May 9, 2008)

Foretelling The Future: Online Prediction Markets &#8212- (4 pages in all)

ABC video

YouTube video

  1. Not a single word about InTrade-TradeSports fucking up its traders during the North Korea Missile episode.
  2. Although James Surowiecki is a great thinker overall, I&#8217-m not happy he served InTrade&#8217-s past forecasting successes in absolute terms &#8212-and not in terms of probabilities. That shows James Surowiecki can&#8217-t be the ultimate leader of the field of prediction markets. Robin Hanson, Justin Wolfers, Koleman Strumpf, Eric Zitzewitz, or even Emile Servan-Schreiber, would have not made that mistake.
  3. All prediction markets are not created equal. Spot that they go too far, saying terrorism prediction markets or earthquake prediction markets could serve a societal purpose. That is complete bullshit. That is pure hype. As I said yesterday, an analyst should check whether a given prediction market is really able of aggregating important information. Just because John Delaney wants to create a betting market to get money doesn&#8217-t mean that that given prediction market will be able to give sound forecasts. Otherwise, we would have prediction markets about future lottery outcomes and we would make a fortune out of that. :-D
  4. Spot that they put the emphasis on the easy translation between the 0&#8211-100 prices and the 0&#8211-100 probabilities. That puts BetFair&#8217-s model (based on those damn digital/decimal odds) out of the picture.

Prediction Markets & Data Visualization

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Spot that that guy didn&#8217-t say, &#8220-I monitor a prediction market&#8220-. He said, &#8220-I monitor a chart&#8220-.

InTrade, TradeSports, BetFair, TradeFair, NewsFutures and HubDub have a huge work to do to improve their charts. In the future, they will output richer charts. Customizable, dynamic, compound charts, with news markers.

STRAIGHT FROM OUR U-TURN DEPARTMENT: Here are the VP prediction markets -all of them.

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Don&#8217-t you love the Web? Within 15 minutes after my posting my absolute and definitive refusal to publish any bits about the VP prediction markets, I received a long rebuttal by Google&#8217-s Bo Cowgill &#8212-whose great prediction market paper is still for you to download (PDF file), by the way.

Okay, Okay, Okay.


InTrade

Democratic Vice President Nominee

Price for 2008 Democratic Vice-Presidential Nominee at intrade.com

Price for 2008 Democratic Vice-Presidential Nominee at intrade.com

Price for 2008 Democratic Vice-Presidential Nominee at intrade.com

Price for 2008 Democratic Vice-Presidential Nominee at intrade.com

Republican Vice President Nominee

Price for 2008 Republican Vice-Presidential Nominee at intrade.com

Price for 2008 Republican Vice-Presidential Nominee at intrade.com

Price for 2008 Republican Vice-Presidential Nominee at intrade.com

Price for 2008 Republican Vice-Presidential Nominee at intrade.com

BetFair

Next Vice President:

Democratic Vice President Nominee

Republican Vice President Nominee

NewsFutures

Barack Obama will pick a woman as running mate.

© NewsFutures


Explainer On Prediction Markets

Prediction markets produce dynamic, objective probabilistic predictions on the outcomes of future events by aggregating disparate pieces of information that traders bring when they agree on prices. Prediction markets are meta forecasting tools that feed on the advanced indicators (i.e., the primary sources of information). Garbage in, garbage out&#8230- Intelligence in, intelligence out&#8230-

A prediction market is a market for a contract that yields payments based on the outcome of a partially uncertain future event, such as an election. A contract pays $100 only if candidate X wins the election, and $0 otherwise. When the market price of an X contract is $60, the prediction market believes that candidate X has a 60% chance of winning the election. The price of this event derivative can be interpreted as the objective probability of the future outcome (i.e., its most statistically accurate forecast). A 60% probability means that, in a series of events each with a 60% probability, then 6 times out of 10, the favored outcome will occur- and 4 times out of 10, the unfavored outcome will occur.

Each prediction exchange organizes its own set of real-money and/or play-money markets, using either a CDA or a MSR mechanism.

Why I dont believe in VP prediction markets

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Because the decision to select a running mate is a decision made in secrecy, with many (personal or else) factors we are not aware of, and many things we are not fully informed about. Barack Obama and John McCain&#8217-s minds are not that open &#8212-whatever you can read in the Press from the so-called campaign insiders. That&#8217-s the typical kind of prediction markets that traders and probability seekers should not approach.

So, I won&#8217-t cover InTrade and BetFair&#8217-s VP prediction markets, here.

Charles Plott (a big-shot economist) condemns all the hype surrounding the prediction markets and the wisdom of crowds.

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California Institute of Technology economist Charles Plott:

What you&#8217-re doing is collecting bits and pieces of information and aggregating it so we can watch it and understand what people know. People picked this up and called it the &#8216-wisdom of crowds&#8217- and other things, but a lot of that is just hype.

Prediction Markets: A new Special Interest Group on forecastingprinciples.com

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The marketsforforecasting.com Special Interest Group provides a resource for researchers and practitioners who are interested in the field of prediction markets.

In keeping with the objectives of forecastingprinciples.com, this SIG will present research findings that support evidence-based principles. In particular, the site covers research that provides guidelines, prescriptions, rules, conditions, action statements, or advice about what to do in given situations.

The current site is a beta-version. To further develop the content, we ask for your contributions!

The material for this special interest group is maintained by Andreas Graefe. Please contact him for further information, and with corrections, additions, or suggestions for these pages.