GIGO and prophets, tears and markets

No Gravatar

Prediction markets failed to accurately predict the unexpected effect a few tears had on the New Hampshire primaries- and some analysts rushed to blame the tool and undermine its reliability and applicability. Let me restate some fundamentals and my view, in a snapshot:

  • Markets are not prophets, prophets do not exist.
  • A mechanism&#8217-s forecastability should not be judged against a virtual fool-proof prophet- we&#8217-d better compare it with other existing or widely-used mechanisms and -to my partial and context-bound knowledge- markets outperform all those.
  • Markets are the only tool that intrinsically suggests their probability of failure. If Obama&#8217-s stock is traded at 70 cents, this suggests that there is a 30% probability of Obama losing- I&#8217-d say markets are by character modest and no fanfare has any place in describing their suggestions.
  • Markets are primarily an aggregation/meta mechanism- as such, garbage-in-garbage-out effects are expected to happen, so we&#8217-d need to keep focus on minimizing garbage rather than blaming the market/compiler.
  • Maturity of the mechanism and its use, as long as trading volume (in real-money intrade for example), have not yet reached a fully efficient level (more on this to come soon), but these result in significant profit opportunities, so I expect things to just keep getting better.

cross-posted from my blog

Who did best in explaining the prediction markets to the lynching crowd?

No Gravatar

After the New Hampshire fiasco, 16 18 people came to defend the prediction markets, so far. So far, the best takes are from:

  1. George Tziralis
  2. Robin Hanson
  3. Jonathan Kennedy
  4. and I&#8217-ll give the 4th spot to a combo, mixing takes from John Tierney, Adam Siegel (surprisingly pertinent &#8211-I bet he is on a fish diet, post Christmas :-D ), and Steve Roman.
  5. UPDATE: &#8220-Thrutch&#8220-, Emile Servan-Schreiber and Panos Ipeirotis.

AWOLs (so far): PMIA, AEI-Brookings, InTrade, TradeSports, BetFair, TradeFair, NewsFutures, Emile Servan-Schreiber, Jed Christiansen, Koleman Strumpf, Bo Cowgill, Richard Borghesi, Chris Hibbert, David Perry, Ken Kittlitz, Paul Tetlock, David Pennock, Mike Linksvayer, Brent Stinsky, David Yu, Mark Davis, David Jack, James Surowiecki, Tyler Cowen, Greg Mankiw, Donald Luskin, John Delaney [*], etc.

[*] Steve Bass tells us that John Delaney&#8217-s pre-NH CNBC appearance was awesome. I was up that day, waiting for that CNBC segment, but failed to spot it. If somebody sends me the YouTube link, I&#8217-ll publish it here.

Five Reasons the Prediction Market Critics Are Wrong.

No Gravatar

1. It really was an upset – As it has been pointed out elsewhere, the Clinton victory was a surprise to everyone. Favorites can lose. But so what? Ordinarily, that’s not a market flaw or a reason to doubt the odds shown in the market.

Justin Wolfers article in the WSJ had the best summary:

Against this background, it is no exaggeration to term the result truly historic. Not that there haven&#8217-t been more dramatic upsets or come-from-behind wins that carried more significance &#8212- this was just an early primary, albeit a pivotal one. But in terms of unpredictability, or at least the failure of everyone to predict it, it may have no modern match.

Historical comparisons are already being drawn between the New Hampshire primary and the famous 1948 presidential race…Yet the magnitude of the Clinton surprise is arguably even greater&#8230-Thus, Sen. Clinton&#8217-s victory on Tuesday was more surprising than President Truman&#8217-s in 1948.

Given the above, were the Clinton prices on Intrade very far off? It&#8217-s not obvious that they were.

2. Pundits/Critics are NOT traders – If I believe a contract should be trading around 30 and I see it trading at 7, it would make my day. As a trader, seeing a contract that is clearly mispriced is a good thing. Traders who remember the French politician Le Pen’s strong showing in 2002 vs his polls or who read Steve Sailer’s blog should not be surprised that people are dishonest with pollsters. However, to a pundit, an isolated incident of mispricing means the entire concept of prediction markets is faulty.

Since NH results, pundits have been asking, “Are prediction markets flawed?” The traders who make and move the market don’t believe so- they are trading more than ever. In any case, there were no postings on the 7th of January about how wrong the prediction markets are, only after-the-fact postings demonstrating perfect 20/20 hindsight. Traders, not critics, will determine the success of the prediction markets.

Let us not forget that pundits have an agenda too. For some, especially political ones, they need to present themselves as being able to offer insight that no one else has. Since prediction markets allow events to be quantified in real time, the pundits have less to add. This makes critics especially eager to take some of the shine off prediction markets and make themselves look smarter by comparison.

Additionally, there is a contingent of commentators and bloggers with an anti-market bias who delight in seeing any market based tool be wrong. They will be the first to loudly smear PM errors but no where to be found when the market turns out to be right.

3. PMs are not polls – This common mistake is exemplified by this quote from the Chicago Tribune, “The New Hampshire primary was a reminder that prediction markets, where bettors are putting money on the line, can have no more value than opinion polls, where participation costs nothing.” This critic missed the point and doesn&#8217-t realize he is comparing apples and oranges.

Most commentators have focused on the accuracy of the market prices without touching on the underlying purpose of the market: speculation and hedging. Even if the polls are no more accurate than the market, they still can’t be used for trading functions.

4. Regulations have hurt the accuracy and liquidity of PMs – The inconvenience of opening a trading account at Intrade has excluded many Americans from participating. What is the cost of accuracy to the PMs? Surowiecki’s The Wisdom of Crowds lists four factors necessary for a wise crowd: diversity of opinion, independence, decentralization, and aggregation. At least two of these have been highly restricted due to regulations. Even so, the market is usually more accurate than the polls. None of the critics has pointed out that with so many potential traders cut off from trading, the market is surely excluding informed participants.

5. “Serious people who study or work with these markets are not in the &#8216-markets are magic&#8217- camp” – Prediction markets are like other financial markets: fat tails, black swans, bubbles, “manipulations” etc. These are all visible in housing, equities, and fixed income markets as well and no one speculates about the end of those instruments. As Eric Zitzewitz pointed out, the “markets are magic” crowd is just a strawman and not a logical basis to attack prediction markets.

Digg Link:

http://digg.com/business_finance/Top_Five_Reasons&#8230-

VENERABLE LAW SCHOLAR CASS SUNSTEIN REBUTS PAUL KRUGMAN AND COMES OUT TO DEFEND THE PREDICTION MARKETS.

No GravatarCass Sunstein:

[&#8230-] Some people are now doubting not only the prediction markets but also the polls, saying that no one knows anything, and that anything is as likely as anything else. Don&#8217-t believe it. To be sure, we are continuing to obtain information about how prediction markets perform and when they do well and poorly. Perhaps they will turn out to be less reliable than they seem &#8212- and in all likelihood, we will obtain a better understanding of when they work. And of course no one has a crystal ball. But the polls are generally pretty good &#8212- and if you want to have a sense of the probabilities, you&#8217-d probably do best to consult Intrade.

Thanks to Stephen Bass for the link.

Previous blog posts by Chris F. Masse:

  • Red Herring’s list of the top 100 North-American high-tech startups includes Inkling Markets —but not NewsFutures, Consensus Point, or Xpree.
  • Professor Koleman Strumpf explains the prediction markets to the countryland people.
  • Professor Koleman Strumpf tells CNN that a prediction market, by essence, can’t predict an upset.
  • Time magazine interview the 2 BetFair-Tradefair co-founders, and not a single time do they pronounce the magic words, “prediction markets”.
  • One Deep Throat told me that this VC firm might have been connected with the Irish prediction exchange, at inception.
  • BetFair Rapid = BetFair’s standalone, local, PC-based, order-entry software for prediction markets
  • Michael Moore tells the Democratic people to go Barack Obama in Pennsylvania (a two-tier state), but the polls and the prediction markets tell us that that won’t do the trick.

HUBDUB = where the news shape the future

I like the motto dreamed up by Nigel Eccles and his Scottish team. [I think they&#8217-ll come up with a play-money prediction exchange, but I&#8217-m not sure exactly what they are doing up there.]

And he, too, has come up to the defense of the prediction markets.

[I have updated my list of PM friends. Quite a long list now.]


Author Profile&nbsp-Editor and Publisher of Midas Oracle .ORG .NET .COM &#8212- Chris Masse&#8217-s mugshot &#8212- Contact Chris Masse &#8212- Chris Masse&#8217-s LinkedIn profile &#8212- Chris Masse&#8217-s FaceBook profile &#8212- Chris Masse&#8217-s Google profile &#8212- Sophia-Antipolis, France, E.U. Read more from this author&#8230-


Read the previous blog posts by Chris. F. Masse:

  • Barack Obama is the 44th US president.
  • We already have prediction markets in future tax rates. It’s called the municipal bond yield curve.
  • DELEGATES AND SUPERDELEGATES ACCOUNTANCY
  • O’Reilly – Money-Tech Conference
  • Google Profiles
  • Event Derivative Exchange HedgeStreet is baaaaaaaaack… from the grave.
  • Sports Derivative Forum

THE SILICON ALLEY BLOG COMES TO THE RESCUE OF THE PREDICTION MARKETS.

No Gravatar

Silicon Alley&#8217-s Jonathan Kennedy:

[…] In denouncing prediction markets as &#8220-wrong,&#8221- however, many pundits miss the point. Prediction markets do not provide accurate predictions of the future. (How could they? They simply represent the consensus guess of a group of people who aren&#8217-t prophets). They merely provide the most-informed guess as to what that future is likely to be.

As numerous &#8220-collective wisdom&#8221- studies have shown, the consensus guess is always better than the majority of the individual guesses that are factored into it (not sometimes&#8211-always). The collective wisdom, moreover, is often more accurate than that of ANY individual. Why? Because the market collectively incorporates far more information than is available to any one individual.

Like the stock market, prediction markets don&#8217-t get it right every time. They do, however, provide a useful window into the collective expectations of others&#8211-one that is often the best available estimate of the future. And they do sometimes get it right. Just as they did with Mr. McCain.

Bravo, mister Jonathan Kennedy.

&#8212-

Take that, Barry Ritholtz. :-D

In an upcoming post, we will review the strengths and weaknesses of these thinly traded prediction markets&#8230-

We are holding our breath, Barry. Hurry up.

The answer to any anti-prediction market backlash is quality, impartial, exchange-independent, science-based, diligent, pro-PM blogging.

No GravatarIs John Delaney the greatest psychic of all times (past, present, and future)?

Deep Throat is very impressed by how accurate the InTrade-TradeSports CEO&#8217-s 2005 prediction turned out to be. According to Deep Throat, the great Irish oracle &#8220-accurately predicted back in early 2005 in a PM conference in NY that someday the markets will make a horribly wrong prediction and that the [prediction market] industry will take a lot of s**t for it.&#8221-

Hummm&#8230-.

Deep Throat is easily impressed. What about the prediction below, then:

  • One of these days, a powerful hurricane will land in one of the southern states, and make billions of dollars in damage.

Vague and obvious predictions are of little help, here. An interesting thought to have, collectively, is how to prepare well in advance to counter such a backlash &#8212-as it is sure to happen again in the coming years. Due to the readers&#8217- new behavior (using the Web to get their info), the conversational aspect of the Web (comments, bloggers responding to their peers), and the velocity of the bloggers (tempests in tea cups spread over one or two days, and then the bloggers move on), the answer is quality, impartial, exchange-independent, science-based, diligent, pro-PM blogging.

You will note that InTrade-TradeSports, BetFair, NewsFutures, and the other PM firms, are completely absent from the dialogue between anti and pro PMs. The BetFair blog has not published anything about the New Hampshire fiasco, and the InTrade bulletin has only put in writing, on a post, the post-NH market-generated probabilities &#8212-without adding any bit of analysis. Totally pointless and useless corporate publications.

As for me, I have worked hard to put our group blog, Midas Oracle, on the blogging scene. I will further this endeavor and announce new initiatives in the future &#8212-if I am able to do so.

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.

The prediction markets deserve a fair trial.

No Gravatar

Niall O&#8217-Connor:

Sadly, from our analysis, the impression that one gets is of a market that is spooked by poll results– driven by stale news- and heavily influenced by gossip and rumour.

Questions:

  1. Could Lord O&#8217-Connor cite the name of a more accurate forecasting tool?
  2. Could Lord O&#8217-Connor publish his own track record at predicting the US and British elections?
  3. Could Lord O&#8217-Connor give one example of an infallible human institution?
  4. Could Lord O&#8217-Connor state publicly whether he believes in knowing the future in advance with 100% accuracy? (If yes, then I&#8217-ll suggest to the CIA to hire him to get Bin Laden.)

Previously: Prediction markets are forecasting tools of convenience that feed on advanced indicators.

Felix Salmon slams Wall Street Journals Justin Wolfers -but not Chris Masse.

No Gravatar

Felix Salmon:

[…] And thirdly, if you&#8217-re Justin Wolfers, it&#8217-s probably smart not to make unhedged statements saying that Barack Obama has &#8220-better than a nine-in-ten chance of winning&#8221- the New Hampshire primary. […]

Previously: Prediction markets are forecasting tools of convenience that feed on advanced indicators.

Since Chris must sleep at some time (I think)…

No Gravatar

&#8230- I&#8217-ll alert you to a developing story. [Slate’s Daniel Gross: Why were the political futures markets so wrong about Obama and Clinton?]

Thanks to a friend.

~alex