Every picture tells a story

by Daniel on January 21, 2004

[I’ve moved the picture below the fold to save bandwidth]

Can we no longer hear about the “predictive power” of the Iowa Electronic Markets, please? They were bamboozled to exactly the same degree as the rest of us.

[UPDATE]: A couple of people in comments have pointed out that this market is for the nomination, not the Iowa Caucus itself. Fair point, but sadly, no. Either the Iowa Caucus is an important determinant of who gets the nomination, or it isn’t. If it isn’t, there shouldn’t have been anything like this sharp movement on the 19th. If it is important, then trading in these contracts ought to have reflected relative chances of winning in Iowa. Either way, big spikes like this on news days are not consistent with semistrong market efficiency. I’d also note that the Iowa Electronic Markets are strongly linked with Iowa University’s business school, so the Iowa caucus is their best chance of having local tacit knowledge. While we’re noting things, I’d make a few points on the alternative prediction methods. The Irish Independent’s online poll seems to have done at least as well as IEM if not a little better (fair enough, I don’t have a time series for this one), and BBC Newsnight ran a big feature on Kerry last week; they’d clearly picked up the buzz.

iowa.jpg

Bonus Arbitrage Update: Mark Kleiman is posting the IEM and Tradesports numbers every day on his weblog, and I haven’t seen a single day so far when there hasn’t been at least one arbitrage between them. Today’s is Buy Clinton@1.8 on IEM and Sell Clinton@2.5 on Tradesports. (NB this isn’t investment advice). I’d also point out that the arbs aren’t always this small and aren’t always in the small long-odds contracts; on Tuesday you could have bought Kerry@33.8 on Iowa and sold him @ 36.1 on Tradesports. I haven’t got an Iowa account and can’t be bothered getting approved to have one, but anyone who cares can make a few bucks a day trading the two against each other.

{ 52 comments }

1

WillieStyle 01.21.04 at 9:46 pm

Who’s ROF?

2

GT 01.21.04 at 9:48 pm

You are 200% right.

If you looked at the equivalent chart for the 2000 election you’d see the exact same thing.

3

David W. 01.21.04 at 9:54 pm

“ROF” = Rest Of Field

4

Chris Lightfoot 01.21.04 at 10:26 pm

Surely the point about these things is that they summarise all publically-available information about the election, not that they are “predictive”? When the available information changes, the market shifts.

5

Linc Wolverton 01.21.04 at 11:19 pm

FYI: ROF in this case is mostly driven by Edwards.

Some points about stock movements.

1. The market, from what I understand, has a heavy influence from college campuses, where Dean rides high. This bias, however, likely will be discounted from now on.
2. The market is defined as the winner at the convention, and each candidate will have his or her ups and downs–and, like a financial stock market, there will be corrections.
3. Information prior to recent days Iowa did not take into account of what one Iowa voter said: “Dean does not wear well.” It was hard for the market to discount how well Dean wears until the first major test.
3.

6

sam 01.21.04 at 11:33 pm

Looks like Dean’s volatile internet campaign ended with a blow off top.

7

Walt Pohl 01.21.04 at 11:47 pm

Daniel: From the moment I first saw that chart a couple of days ago, I knew it was only a matter of time before you posted it.

8

Anticipatory Retaliation 01.22.04 at 12:57 am

One might note, that despite the surprise, the Dean track started to take some big hits in early November, and then again before Christmas.

Perhaps this is like the stockmarkets and really has no predictive value (save that that some claim is produced by ‘technical analysis’).

9

Michael Pollak 01.22.04 at 1:18 am

You’ve hit it right on the head. The myth of the accuracy of these markets’ predictions rests on the Psychics’ Defense. They holler every time they’re right. And when they’re wrong they forget about it.

Of course, everyone sees through this when psychics do it, because no one believes in psychics. But no one sees through it when markets do it because we believe in markets. It’s the defining faith of our age. If you don’t believe in their omniscience and omnipotence, you are by definition irrational.

I’m not sure you can undermine faith with arguments. I think eventually they make you drink poison hemlock.

Michael

10

sidereal 01.22.04 at 1:43 am

Classic.

Clearly the aggregate knowledge of a bunch of people who have no idea what’s going to happen is a powerful tool.

Let’s get started on that terrorism market.

11

Bryant 01.22.04 at 2:56 am

“Can we no longer hear about the ‘predictive power’ of the Iowa Electronic Markets, please?”

Sorry, nope. The graph above is a graph showing stock prices for the nomination, not stock prices for the Iowa caucuses. Since the nominee hasn’t been determined yet, it’s a little early to start throwing stones.

It does point out the danger of mistaking a point in the process for the final decision, which I imagine is a mistake quite likely to be made while interpreting any market of this type.

12

praktike 01.22.04 at 2:56 am

this is for the *nomination*

13

Brad DeLong 01.22.04 at 3:06 am

You’re just sore because you put on a large leveraged position long Dean on January 2…

14

Katherine 01.22.04 at 3:12 am

This ROF fellow sounds almost as appealing as that dashing Unnamed Democrat….

Sorry if that’s not actually funny. I bought into Dean in March 2003, and I’m with him till he drops out. But Christ, this is depressing.

15

Brian Weatherson 01.22.04 at 3:13 am

I think we should take seriously the possibility that the objective chance of Dean getting the nomination was 0.76 back in November and is now 0.34, and that in general this market has been tracking objective chances perfectly. I mean, it’s consistent with the data, and we all know how well markets are supposed to work.

16

James Surowiecki 01.22.04 at 4:35 am

I realize these points have been made myriad times (often by me) to no effect, but once more into the breach . . .

The question about something like the IEM is whether it is better, on average, than other predictive mechanisms. Contrary to what Michael Pollak insists on arguing, no serious person has made claims for the omniscience or omnipotence (and I don’t even know what that means in this context) of the IEM specifically or markets generally. His creation of a straw man that he can batter adds nothing to the discussion.

As a result, the only relevant question is how the IEM is doing/has done compared to other predictive mechanisms and/or individual predictors. The chart Daniel posted gives us no information about that comparison. And of course, as praktike and others have pointed out, the market was not trying to predict the outcome of the Iowa primary. It’s trying to predict who’s going to get the Democratic nomination. I’m not sure how we can say the market is wrong until we know the answer to the question it’s trying to answer.

It is true, obviously, that the market thought one thing on Jan. 16 and something very different on Jan. 21. But the information that was available in the world — public and private — was very different on Jan. 21 than it was on Jan. 16. Saying that the market didn’t foresee the change in information certainly demonstrates that it is a far-from-perfect predictor of the future. It does not demonstrate that its analysis of the information on Jan. 16 was worse than those of other predictive mechanisms. Certainly anyone who didn’t ratchet down his expectations of the likelihood of Dean’s success after watching his “concession” speech on January 19 would have been very foolish.

To take only the most extreme example, if Howard Dean had been hit by a car while crossing the street on Jan. 18 and died, the IEM’s forecast would undoubtedly have been wrong. Would that demonstrate that the IEM was useless? No. The IEM is not a crystal ball. It’s simply been, over time, better than the mechanisms we have traditionally relied on to predict election outcomes.

Michael Pollak says that defenders of the IEM cannot be convinced by evidence. Here’s the evidence: in 49 different elections between 1988 and 2000, election-eve prices in the IEM were, in absolute terms, off by just 1.37% in presidential elections, 3.43% in other U.S. elections, and 2.12% in foreign elections. That seems pretty good to me, but I’m statistically naive. More important, though, over the course of the presidential elections between 1988 and 2000, for instance, 596 different polls were released. Three-fourths of the time, the IEM’s market price on the day each of those polls was released was more accurate — that is, it was a better predictor of the election’s ultimate outcome. Now, we can argue about what this means — John Quiggin, for instance, has argued that doing better than the polls is a meaningless standard. But it certainly means one thing: it is not the defenders of the IEM who are relying on faith instead of argument.

I confess that what really baffles me is the hostility (not from dsquared, but from other posters) to the idea that aggregative mechanisms like markets might be of use in predicting the future. Who loses if markets or betting pools are found to be superior predictors than the ones we use now? Assuming there is a social benefit to reducing uncertainty, it seems foolish to reject these experiments for ideological reasons. And it seems to me that the track record of these mechanisms is solid enough that we’d be better off spending our time figuring out when and why things like the IEM go wrong — for instance, an obvious question is whether the strong Internet presence of Dean supporters skewed the IEM prices before Iowa — rather than ranting about the supposed evils of market worship. But then, I have a dog in this fight, so take my earnest appeals with a grain (or many grains) of salt.

17

zizka 01.22.04 at 6:00 am

One question is whether the numbers were gamed or distorted by frenzied Deanies. In which case, they lost their small amounts of money, as they deserved, but if they were trying to get a bandwagon effect before the election they attained that goal in a small way.

When the cost of buying in is much, much, smaller than the value of electing a president, as soon as the poll starts getting taken seriously (i. e. can be even a small factor in the election, at a cost which is also small) it seems to me that it will be gamed. Even if the people who are gaming it are fooling themselves.

Meaning that the poll was pretty good when it wasn’t being taken very seriously.

18

Michael Pollak 01.22.04 at 6:48 am

James Surowiecki takes my flippant comments far more seriously than they deserve, by which I feel honored, because he knows much more about these things than I do.

I am perfectly willing to admit the efficacy of the IEM as an election eve predictor. There seems nothing mysterious about that. It seems to operate on the same time-honored principles that set odds for horse racing, where too the favorite usually wins. And I’d be willing to bet the track odds predict the outcome of the race better than a poll of trackside observers would too.

What both horse races and elections have in common is that we know when the event in question will happen.

Now what terrorism markets presume (and markets of that sort were the target of my comments; I’m sorry that was obscured in pith) is that this sort of mechanism could be useful when we don’t know when events will happen — that they could somehow predict, or indicate, that it was likely that an event would happen soon. For that to be possible, it seems to me, changes would have to show up in their prices trends in advance of changes in the world’s general appraisal. In the way they didn’t here.

You see to be saying, quite reasonably, that that’s impossible. Markets only incorporate publicly known information. So they can’t by nature know that something will happen before the rest of us do.

That would seem to make a market that would predict terrorist events impossible on principle. Would you agree with that?

If so, I don’t think we have any argument.

19

Matt McIrvin 01.22.04 at 6:59 am

One thing I noticed, watching the numbers evolve, was that as Dean went up in the nomination market, the “Bush over Dean” price in the general election market went up even higher, and the gap seemed to widen disproportionately as if Dean’s perceived electability were actually decreasing as his stock rose.

I’m not sure whether that means the market was being gamed by Dean fans, or not. My guess at the time was that the traders tended to skew Republican; they were buying into the “stupid Dems are walking right into the Dean trap” story. That would also explain the persistent overvaluation of Hillary Clinton.

20

Chris Bertram 01.22.04 at 7:39 am

Brian, do you _really_ want to say that this might be tracking objective chances rather than, say, the degree of credence that it’s rational to have? (You know more about this area than I do but it looks a bit wild to me to say that the probability at t-n of Dean winning at t is an objective property.)

21

sd 01.22.04 at 7:53 am

I think that the IEM was particularly likely to undergo a major correction after the Iowa caucuses – because of the unusual nature of those contests.

The Iowa caucuses are not normal elections, where there is one round of voting, held in secret, and each voter only gets to register their “first choice.” Rather, there are potentially multiple rounds of voting for any given voter (if a candidate fails to get 15% of the first round vote in a given precinct, then his voters have to either choose one of the candidates who did get over 15%, or leave). And the vote is not held in secret (which allows social forces to shape the outcome). Further, delegates are assigned to each precinct based not on population, but on turnout of registered (in this case Democrats) party members in the last general election. And of course the caucus process is so onerous that only a tiny handful of dedicated partisans bother to vote at all.

Put all these factors together and you get an outcome that is unusually hard to predict because of the underlying complexity of the process. Market boosters (like me) are not surprised by this. After all, the Beta on a biotech start-up is much higher than the Beta on an old guard industrial chemicals manufacturer. When the events underlying the performance of the “security” are more complex, the market will adjust to changes in information more dramatically.

In this year’s Iowa election we had an odd situation where the frontrunner (at least for most of the last few weeks – up until the last couple of days before the election), was the second choice of almost nobody. In a straight primary, Dean would have probably finished a few points behind Kerry, which is what the tracking polls indicated. But in the caucus room, in precincts where Gephardt didn’t get 15% of the vote, his people broke for Kerry and Edwards; where Sharpton didn’t get 15% (pauses to consider Iowa electorate and image of lim(x)=0 pops into head), his people broke for Kerry and Edwards. You get the drift.

Unfortunately for Dean (and fortunately for those of us who will probably vote for Bush but who consider a Kerry or Edwards administration mearly displeasing, rather than bone-chillingly scary), the winner in Iowa gets a rejuvenating bounce, and now the momentum has turned against him. If New Hampshire were the first election then I’d still be reasonably confident that Dean would win the nomination. Now I’m not so sure – I think “Other Than” has a little better than a 50% chance right now, and if Dean doesn’t win next Tuesday, I’d put his chances at below 25%, maybe below 15%.

Again, I don’t think this impacts the chances of Dean becoming President. Even if he had sewn up the nomination early it would only be a matter of time before he bit the head off of a small child at a campaign rally (PENNSYLVANIA!!!!!!!!!! MICHIGAN!!!!!!!! **Gobble Gobble** OKLAHOMA!!!!!!). But it does significantly change the chances of Some Democrat winning in November. I’d say Bush is still the favorite, followed by Edwards (materially lower chance than Kerry of winning the nomination but much higher chance of winning the general election if nominated), Kerry and then Clark (Who’s looking more and more batshit crazy every day).

The IEM will do a much better job at predicting the New Hampshire primary, and the general election for that matter.

22

dsquared 01.22.04 at 8:16 am

Heh. My old sparring partner James S writes:

But the information that was available in the world — public and private — was very different on Jan. 21 than it was on Jan. 16.

But come on, man. This is the Iowa Electronic Markets, run by Iowa University’s business school, being caught totally by surprise by the Iowa caucus. I don’t have the specific numbers to hand, but it seems very plausible to believe that there are a lot of Iowa residents in the betting pool. This was the best possible case study under which the IEM might have had specific, local knowledge not contained in the polls.

And they didn’t. Dean doesn’t start falling and Kerry doesn’t start weakening until 10 Jan. Kerry’s local surge was on Newsnight in the UK last week, so one would have thought that somebody might have picked up on it locally.

23

dsquared 01.22.04 at 10:11 am

SD: But aren’t markets meant to be adapted to exactly this kind of high-dimensional problem? Instead, they’ve slavishly tracked the opinion polls up until Iowa, then done the switcheroo on the basis of Iowa. That’s not consistent with semistrong form efficiency, as far as I can see. Furthermore, I reiterate my point above to James:

The IEM will do a much better job at predicting the New Hampshire primary

Kidding, right? They aren’t the New Hampshire Electronic Markets!

24

john s 01.22.04 at 10:14 am

dsquared, when you say “This is the Iowa Electronic Markets, run by Iowa University’s business school, being caught totally by surprise by the Iowa caucus. I don’t have the specific numbers to hand, but it seems very plausible to believe that there are a lot of Iowa residents in the betting pool…”, you fail to note praktike’s point above that the market is for the nomination. Kerry’s performance in Iowa doesn’t wrap up his nomination.

In any case, as I’ve said in other posts on this same subject, I don’t really see that election outcomes are such good tests for markets. Only God has the inside information to make money out of this market. Everybody else is just guessing.

The fact, as James points out, that markets do nevertheless perform as well as they do in predicting election outcomes is therefore interesting.

What futures markets do seem good for, by contrast, are events such as horse racing or terrorism characterised by asymmetric information: some people knowing a lot more or having a better insight than others. Markets can help reveal their information in very simple form: a price.

Dsquared may be right that these markets are no good. But I totally concur with James when he writes:

“Who loses if markets or betting pools are found to be superior predictors than the ones we use now? Assuming there is a social benefit to reducing uncertainty, it seems foolish to reject these experiments for ideological reasons.”

And, unlike James, I don’t have a hat in the ring.

25

dsquared 01.22.04 at 1:09 pm

Couple o’ disagreements here:

you fail to note praktike’s point above that the market is for the nomination. Kerry’s performance in Iowa doesn’t wrap up his nomination.

A fair point, but not one that you can make as a believer in IEM. IEM thinks that the Iowa result makes Kerry much more likely to win the nomination.

I don’t really see that election outcomes are such good tests for markets. Only God has the inside information to make money out of this market.

I don’t see that this is true at all. Everyone has a vote, and everyone talks to people who have a vote. Far more people could be assumed to have a sensible opinion on who will win the election than the price of orange juice futures.

What futures markets do seem good for, by contrast, are events such as horse racing or terrorism characterised by asymmetric information: some people knowing a lot more or having a better insight than others.

I think you have to do a fair old bit of work to construct a category which includes “horse racing and terrorism”. And this is again not obviously consistent with what we know about markets; all the really well-functioning markets try to ensure (through fair disclosure and insider dealing laws) that there aren’t any such information asymmetries.

Who loses if markets or betting pools are found to be superior predictors than the ones we use now?

Well nobody. But we’ve got a lot to lose if they turn out to be worse, and we’ve in the interim turned over our intelligence systems to them on a point of ideology.

26

Brian Weatherson 01.22.04 at 2:22 pm

Chris, I was being somewhat tongue-in-cheek. It’s a really interesting question whether there is such a thing as the objective probability of, say, Dean winning the nomination. If everything is reducible to microphysics, then the answer is definitely yes. If not, it’s a little trickier.

The serious points I wanted to make were (1) if there really are chances (or something like them) bouncing around here the IEM might (for all the data says) be in some sense a perfect predictor, but (2) that’s a very hard claim to defend in practice. In reality, the objective chance of Dean winning (if such a thing is defined) was not that much different an hour after the caucuses ended than an hour before they started, but that’s obviously not how the market behaved. In general I agree with dsquared’s point (or what I take to be his point) that the markets here are not doing a better job of synthesising existing data than a relatively smart person with a web connection could do.

27

James Surowiecki 01.22.04 at 3:33 pm

Lots of good posts here. Sorry I was asleep when they went up, and am responding so late. Anyway, a few things:

With regard to Michael Pollak’s comment, I don’t think that markets can only incorporate publically available information. Ideally, they provide an incentive for people with private information to reveal it as well. But I agree with him that markets — or any aggregative mechanism — have little chance of predicting an event that no one (or only a tiny number of people) knows is going to occur (like, say, a terrorist attack). There is one caveat to this: I still think that closed internal markets (or some other aggregative mechanism) would be useful within the intelligence community as a means of circumventing political and bureaucratic hurdles, and I think these might have some predictive power. To offer one concrete example, if there had been an internal market on the probability that WMD would be found in Iraq, I suspect the market’s verdict would have been very different from the one that the White House relied on (or determined).

I’m with dsquared. I think elections are an excellent testing ground for prediction markets, and I don’t think asymmetric information is a condition for markets working well, so when the IEM does badly we should pay attention. But I do think the nomination market, especially at this point in the process, is a very difficult one to use as evidence for either the positive or negative case, mostly because of the objective probability problem — how will we know, in the end, if Dean did have an objective probability of winning of .76 in November, given the fact that the primaries take place only once every four years (unlike, say, horse races) — and in part because of the volatility of voter preferences. I tend to think the vote-share markets (where the outcomes are unmistakably accurate or inaccurate) are better tests. Of course, this may point to the limits of markets’ predictive capabilities.

One of the things I am really interested in is Zizka’s question about gaming. Because the IEM is so small, it’s obviously more easily subject to influence, not by people with deep pockets (since the stakes are limited), but just by an influx of new investors. With more outside commentators paying attention to the IEM — though Daniel may put paid to that one of these days — the political benefits of gaming the market increase (assuming that, as it seems to, perceived popularity ends up influencing actual popularity). The result may be that the more attention people pay to the IEM, the less accurate it will be (although you’d think that in a two-person race, at least, both sides would be trying to game the market, and they would cancel themselves out).

28

praktike 01.22.04 at 3:45 pm

Guys, look at the graph again.

Dean starts to tank and Kerry starts to rise once Dean started feeling the heat and the poll numbers started moving in Kerry’s favor. And if you look closely, you’ll find Edwards tagging along for the ride, and Gephardt tanking.

Isn’t that what happened?

Anybody can cherry-pick individual polls and find that they did a better job. The point is that the markets reflect a synthesis of all available information, not that they necessarily beat every single poll.

I think they’ve done a good job so far, and as I said above, they really haven’t been tested yet, have they?

“Bamboozled” is far too strong a word, Dan.

29

sd 01.22.04 at 3:47 pm

dsquared writes:

“SD: But aren’t markets meant to be adapted to exactly this kind of high-dimensional problem? Instead, they’ve slavishly tracked the opinion polls up until Iowa, then done the switcheroo on the basis of Iowa. That’s not consistent with semistrong form efficiency, as far as I can see. Furthermore, I reiterate my point above to James:”

The ability of a market to accurately predict outcomes through a pricing system is determined by the complexity of the underlying events being priced and and the quality and quantity of research and analysis that are applied to that system. Nobody I know of (and I went to business school at the University of Chicago, where we routinely sacrifice goats to the Efficient Market) seriously believes that the financial markets would still be efficient if the number of people playing in them were much much lower, or if the players didn’t have VERY strong incentives to try to beat the market. The IEM certainly attracts a lot of attention, but somewhat less attention than Wall Street, I dare say. And nobody ever retired on a 50 foot yacht because they analyzed the IEM better than the crowd.

As the complexity of the event being priced goes up, we need more and more and better and better market participation to accurately price the market. The Iowa caucuses are just too complex to be accurately priced by the IEM. If there were $100 million riding on getting it “right,” then you can be sure that the IEM would do a better job. The New Hampshire primary (even the general election) is a much simpler system, and thus the IEM should perform better in predicting its outcome.

30

john s 01.22.04 at 5:05 pm

dsquared:

“Far more people could be assumed to have a sensible opinion on who will win the election than the price of orange juice futures.”

I don’t agree. If I were a Florida orange grower I think I’d be better informed about the likely Florida orange harvest than I would be about the outcome of the Democratic nomination race. It’s not a question about average quality of knowledge, it’s a question of significantly better information held by even a limited number of people.

“all the really well-functioning markets try to ensure (through fair disclosure and insider dealing laws) that there aren’t any such information asymmetries.” This point is addressed to James S too since he seems to support your view dsquared.

Point taken about insider info etc, but I’m still confused here. It’s surely information asymmetries that move futures markets in meaningful ways (ie, predictive as opposed to reactive)? In fact, dsquared, you’re trying to have it both ways; clearly, you argue, the IEM is obviously flawed because despite having a locational information asymmetry (people in Iowa speculating about the outcome of the primary should have had an advantage because they were in Iowa), it performed badly.

My argument is that Iowans don’t have a better idea about the future nomination, they don’t have an informational asymmetry. Nobody does, which is why the latest information from Iowa has driven the latest quotes. But these futures markets are only any good if they actually do predict.

One message I get loud and clear from this discussion is that futures markets may be terminally flawed by an inability for any two people to agree on what they are actually saying.

31

zizka 01.22.04 at 6:38 pm

Conscious gaming aside, the Dean phenomena may also comparable to the fact that, for psychological reasons, horse-track betters tend to put too much money on long shots, and that occasionally a certain horse will pull a lot of bets for superstitious and irrational reasons which are widely distributed (a mania of crowds type of thing).

Dean of course was NOT a long shot in Iowa; my point is that there can be systematic, widespread types of irrational betting which don’t cancel one another out.

However, for insiders in intelligence services, this kind of market COULD send a message in the case when a large proportion of the staff disagree with the conclusions reached by the leadership. As far as that goes, it could also be deliberately used by a faction to send an anonymous message to the leadership. Which wouldn’t necessarily be a bad thing.

P.S. A lot of people lost money on Bob Hope over the years. I’ve wondered whether maybe he actually died years ago, but that his cadaver had come inder the control of gamblers. Of course, a good embalmer could have done a much better job than what we saw for the last several years, but obviously they didn’t want to tip their hand. Good crooks think of stuff like that.

32

Michael Pollak 01.22.04 at 6:42 pm

I’m glad to see James Surowiecki and I are substantially in agreement that a market in terrorism futures would be unable to predict the future — which is the only reason I could imagine for wanting to set one up.

He then proposes a slightly different market with a different rationale: that an internal market might be useful in overcoming bureaucratic barriers to information flow. I’m willing to entertain that idea. But I find this example extremely unconvincing.

In the first place, afaik, not a single person in government or intelligence has yet come forward or even been quoted anonymously saying that he or she thought before the war that no WMD would be found in Iraq. Not one. So even in an alternative universe where people in government set up markets like this all the time, I can’t see where the impulse would have come from to set up this one. It would be seeking the answer to a question no one had. And if it was set up, I can’t see how it could possibly have yielded a different answer.

But let’s imagine an even more alternative universe in which those things were true. Let’s say there are lots of spooks who haven’t yet spoken who always thought it was a crock. And let’s say this market registered their judgment — that it indicated a high probability that Saddam had no WMD.

If this market were secret, it seems obvious to me that it would have had no effect on policy. It would be simply have been one more piece of classified information that was disregarded.

So the only way in which it could have helped would have been if it were public — if it showed there were internal doubts about administration policy. And in that case, I find it very hard to imagine that an administration that slapped down General Shinseki wouldn’t have shut down this persnickety nerd’s toy at the earliest sign of trouble.

And this seems like a problem in general. Aggregative mechanisms present the consensus view of a given community. And given that it is the consensus, I can’t imagine circumstances when the executive branch wouldn’t be hearing it — unless they were actively suppressing it. In which case, they’d suppress the market too.

In sum, it seems to me that the market you suggest as an example would never have been set up; that if it had been set up, it wouldn’t have given a different answer; and that if it had given a different answer, it couldn’t have overcome the bureaucracy — which was the whole justification for trying it. It seems more like a refutation of the idea than an argument for it.

But perhaps you have another example?

33

john s 01.22.04 at 7:01 pm

In fact, on my point on asymmetric information, I become even more confused when I read James’ post again.

The whole point of markets like IEM he writes is “Ideally, they provide an incentive for people with private information to reveal it as well” but then adds in his very next paragraph “I don’t think asymmetric information is a condition for markets working well”.

Probably my problem is down to jargon. When I hear “asymmetric information” I also hear “private information”. Am I wrong to make that link?

34

Sebastian Holsclaw 01.22.04 at 7:27 pm

Lots of useful comments above, so I’ll just comment on this:

“If it isn’t (speaking of the Iowa Caucus importance), there shouldn’t have been anything like this sharp movement on the 19th. If it is important, then trading in these contracts ought to have reflected relative chances of winning in Iowa.”

Here you are making the error of deciding that the Iowa Caucus must either have zero predictive value or 100% predictive value. I would place its predictive value somewhere nearer to the 30% range. Which is to say it has important value, but not deciding value. Also it is not a widespread market, so the value of its information is limited by the narrower range of information available to the very few people who participate in it. Furthermore, you discount the idea that something might have actually changed in the past few days. If people have RECENTLY decided that they don’t like Dean, it might take a whole day or two for that to be reflected. (A whole day, like that was a long unit of time). Also, you fail to note that almost every major non-market source had the same predictive problem if you track say 5-6 days (or even 2-3) before the vote. So as far as this is an information problem, nearly everyone was wrong–markets and non-markets.

In reality I suspect the main problem with the IEM is its small size which allows its ‘market’ to have too limited information.

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James Surowiecki 01.22.04 at 7:32 pm

An internal market roughly like the one I mentioned was part of the FutureMAP program that was killed in the uproar over PAM. PAM — the so-called “terrorist” market — wasn’t actually going to be set up to predict terrorist events. It was going to focus on changes in the economic condition, military preparedness, and civil stability of Middle Eastern countries (all subjects, I remain convinced, that prediction markets could give us good information about). The internal markets, from what little information I’ve been able to glean about them, might have dealt with more specific questions, although even there I imagine the questions would have been relatively broad (perhaps, and I’m just guessing, something like, “What are the chances of a major terrorist attack on U.S. soil in the next 12 months?”) In any case, the point is that there was an impulse in the government –or at least in DARPA and the intelligence community — to set something like this up. Sens. Wyden and Dorgan ensured that the funding for it would be cut off.

As to whether it could have worked, I guess I see the political and bureaucratic hurdles that need to be circumvented differently than you do, Michael. For the most part, I don’t think you get bad decisions and predictions within corporations or governments because of conscious malevolence or manipulation. I think most organizations — and this includes the CIA — want their view of the future to be as accurate as possible. But I think organizational biases influence the kinds of things people will say and the challenges they will offer to what those higher in the hierarchy believe. In a sense, I think the true “consensus” view (I’d say “collective” rather than “consensus,” but no matter) will often not emerge unless there’s a mechanism that allows pepole to express what they really think without fear of reprisal. And since, in many organizations, people are more likely to be rewarded for going along with the boss rather than for being right, the incentives for preferring accurate predictions to politically acceptable ones are small. An internal market is one possible way around that.

It’s absolutely true that there is no guarantee that an administration would act on information that they found uncongenial. But I guess I’m assuming that, over time, most policymakers would want to know what’s true, and not just what they hoped was true, and that if internal markets proved to be better predictors than other mechanisms, they would come to pay attention even when they didn’t like what the market was saying. But I may be naive.

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James Surowiecki 01.22.04 at 7:40 pm

Re: Sebastian’s point, the changes in sentiment among the voters in just a week has been fairly remarkable. One poll today said that the percentage of New Hampshire voters who had a favorable impression of Dean fell from 59% to 39% in the past week. That’s a remarkably volatile electorate. On the other hand, if the IEM were really visionary, it would have seen this coming.

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John S 01.22.04 at 8:43 pm

James, how do you square the two statements:

On markets like IEM: “Ideally, they provide an incentive for people with private information to reveal it as well”

with

“I don’t think asymmetric information is a condition for markets working well”.

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James Surowiecki 01.22.04 at 9:07 pm

To me, “asymmetric information” implies a situation in which a few people know a lot and most people know little or nothing. Certainly in this case markets can work well (as long as the ignorant people are making choices that collectively average out to something close to what the people who know a lot know, because otherwise the ignorance of the many would swamp the intelligence of the few).

But you can also imagine a situation in which people’s knowledge is spread out on a spectrum (or along a bell curve), so that lots of people know something relevant about a question, even if no one person knows everything. In that case, getting people to reveal their private information (and “information” in my usage is a capacious term, including analysis, etc.) would still be essential to getting a correct forecast, even though the information distribution wouldn’t be “asymmetric” in your sense of the word.

(Just as a side note, “asymmetric information” is probably not the best phrase for what you’re describing, since in the economics literature asymmetric information is traditionally used to describe situations where one participant in a potential contract knows signficantly more than the other (like, say, when you’re buying a used car). In many of those situations, asymmetric information leads to market failure.)

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John S 01.22.04 at 10:36 pm

Thanks for that clarification James. Still, it takes me back to my original question about the IEM. Is it really a good test of the predictive power of markets? After all, what private information do people have that they can reveal to IEM about the nomination chances of each of the democratic candidates?

Also, when you write “Certainly in this case markets can work well (as long as the ignorant people are making choices that collectively average out to something close to what the people who know a lot know, because otherwise the ignorance of the many would swamp the intelligence of the few).” it puts me in mind of the Guys and Dolls discussion of betting. Why would someone who knows nothing bet much? That’s the point of futures markets surely? If you know a lot, then you’ll bet and that’ll show up. Why would the ignorance of the many swamp the intelligence of the few? These futures markets should give more weight to those who “know” most.

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James Surowiecki 01.22.04 at 11:03 pm

I think there’s no evidence — experimental, theoretical, or empirical — that people who are right have a better sense of whether they’re correct or not than people who are wrong. To put it more formally, in all of the studies I have seen, there is only a small correlation between a person’s skill level and his confidence in his own skill (assuming, for argument’s sake, that there are people who are individually more skilled at predicting the future than others). People bet and invest when they’re wrong because they think they’re right. If there are a lot more people who are, in aggregate, wrong than right, their bad judgment will swamp the good judgment of the intelligent. This doesn’t mean that smart people don’t matter. They can significantly improve the “group’s” judgment. But they can’t make a difference if most people’s collective judgment is radically off-base.

Take the stock market. We know that in any given year most fund managers underperform the market, and that over a typical 15-year stretch only something like 1-in-10 managers beat the market. The 90% of the managers who are “dumb” command vastly more capital than the 10% who are smart, and they’re deploying it left and right. How — in a literal, mathematical sense — can the 10% be the ones who are dictating the price?

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James Surowiecki 01.22.04 at 11:06 pm

I would think people have better private information about the chances of political candidates than about most things. Their private information would be based on conversations with family and friends, their experience of the current economy, the way their business is going, their sense of how people are reacting to news from Iraq, etc.: all the myriad small things that collectively end up determining election outcomes.

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Michael Pollak 01.23.04 at 1:50 am

James, you say:

_The internal markets, from what little information I’ve been able to glean about them, might have dealt with more specific questions, although even there I imagine the questions would have been relatively broad (perhaps, and I’m just guessing, something like, “What are the chances of a major terrorist attack on U.S. soil in the next 12 months?”)_

But I thought you had agreed that this was precisely the sort of prediction such markets couldn’t make:

_I agree with [Michael] that markets — or any aggregative mechanism — have little chance of predicting an event that no one (or only a tiny number of people) knows is going to occur (like, say, a terrorist attack)._

And yet now you seem to be suggesting this idea has value. Did I miss a step?

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Michael Pollak 01.23.04 at 2:12 am

James, you say:

_As to whether it could have worked, I guess I see the political and bureaucratic hurdles that need to be circumvented differently than you do, Michael. For the most part, I don’t think you get bad decisions and predictions within corporations or governments because of conscious malevolence or manipulation._

But on the contrary — that seems to be exactly what you’re presuming:

_In a sense, I think the true “consensus” view (I’d say “collective” rather than “consensus,” but no matter) will often not emerge unless there’s a mechanism that allows pepole to express what they really think without fear of reprisal. An internal market is one possible way around that._

Unless I’m misreading you, “fear of reprisal” is exactly the precondition that makes such a market useful. If there is no fear or reprisal (in the broadest sense of reprisal) or other systematic distortion, than there is nothing for the market to remedy — because in that case, the collective view will already be emerging more directly through people telling each other what they think and defending their opinions with reasons.

And that leads to my dilemma. If there is systematic distortion, I don’t see why it shouldn’t distort the results of the market (that is, lead to them being ignored or explained away). And if there’s no systematic distortion, then there’s no need to set such a market up because a clearer version of the collective view is already on tap.

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James Surowiecki 01.23.04 at 4:21 am

Michael, with regard to the first point, my caveat about the internal markets was intended to suggest that an aggregative mechanism that tried to tap the knowledge of people with classified information or direct contact with informants (of the kind I assume some intelligence agents have) might be of use in forecasting impending events. “Forecast” is a deliberately vague word, as is the question I chose as an example. Saying that the collective judgment of a group of CIA analysts and agents might offer some useful information about the likelihood of a terrorist attack in the next 12 months doesn’t mean that group would be able to say “the attack will take place on September 11.” Hoping for that kind of fine-grained result is futile. But if the collective verdict was that there was an 80% chance, that would probably be worth paying attention to in how you directed your intelligence-gathering and homeland-security efforts, and the same would be true if the verdict was that there was a 20% chance.

To argue, as you seem to be, that there’s no possibility of such a verdict being accurate is essentially the same as saying that intelligence-gathering is of no use in predicting future events unless the intelligence is of a direct nature (that is, someone says: “X are planning to bomb the cathedral on this date”). That may be right, but I don’t believe it. I suspect that there are small pieces of information that analysts and agents come across every day that individually are not probative, but that if they could be aggregated might be meaningful. An internal market would be one way of doing that (though I also think there are other aggregative mechanisms that could work as well).

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James Surowiecki 01.23.04 at 4:34 am

With regard to the second point, I think our ideas of where the “systematic distortion” comes from are different, which leads to our differenct conclusions about the possible usefulness of an internal market.

I don’t think that mistakes in most organizations are induced by explicit, top-down policies that are meant to silence dissent. I think instead they’re the result of people’s relationships with their department heads, or their division heads, or their fellow VPs, etc., relationships that end up encouraging compromise and going along to get along rather than honest thinking. That’s not the result, in my mind, of malevolence, but rather of the nature of most bureaucracies. So the reprisal I’m talking about isn’t a system-wide reprisal — with, say, the White House punishing agents who speak out of turn — but rather the day-to-day punishments inflicted by immediate superiors worried about covering their asses. The virtue of an internal market is that none of that stuff matters. No individual is responsible for the market’s final verdict — both because the traders would be anonymous and because a market price is a collective judgment — so no one can get blamed for it. I think that would help.

I also think, more practically, that an internal market is very useful in cases where organizations are divided into silos, as the U.S. intelligence community has traditionally been. Again, the division is not the product of malevolence, but it’s clear that there was much less intelligence-sharing going on than there should have been because agencies saw other agencies as rivals. Cultural identity, in a sense, trumped the collective goal of getting good intelligence. In an internal market, people would be rewarded for the accuracy of their predictions. I assume, in that case, the desire to be right would trump cultural identity. And again, since no one agency would be given credit for the final judgment, no agency would have an interest in subverting it.

There’s no doubt, of course, that people higher up the food chain might shut down such a market as soon as it produced judgments they didn’t like. But as I said, I do think in the end most leaders want their picture of their world to reflect the reality of the world, and so if the market proved relatively accurate (that is, better than other mechanisms) I think they would keep using it.

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dsquared 01.23.04 at 7:19 am

How — in a literal, mathematical sense — can the 10% be the ones who are dictating the price?

Under classic market microstructure theory (as in Maureen O’Hara’s excellent book of that title), the answer to this si that the price is set by the marginal buyer, not the average. Informed investors might be a small minority of the total number of shares outstanding, but they could easily be a majority of any given day’s trading volume in companies which are on the move.

Also note that it is entirely possible to have a market in which 100% of investors are basically stupid about 499 stocks in the S&P500 but know everything there is to know about one stock. That’s actually closer to Hayek#s idae of local, tacit knowledge.

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James Surowiecki 01.23.04 at 7:45 am

The “marginal buyer” theory is the classic explanation for how the informed 10% set the price. But I think the idea of the marginal investor is just wrong. Prices are set not just by buying and selling, but also by not buying and not selling. If the price of a stock I — an uninformed investor — own rises on smart sharks’ buying and I don’t sell, my not selling is setting the new price as much as the shark’s buying did, because it’s only my decision (and that of all the other shareholders) to “not sell” that keeps the price at its new level.

Of course, someone is always setting the price on the margin in a purely functional sense, but unless they have enough capital to outweigh the buying (or selling) power of all other investors, they cannot, in any sense, determine the price of the asset. There are no intra-marginal investors in an asset (aside from those who are legally prohibited from selling), because at every moment (not literally, but effectively) an investor is deciding whether to sell or not-sell the assets he owns, and those decisions are as determinative of the price of the asset as any others. (I cribbed all that from something I wrote on Brad DeLong’s site, because even if it’s wrong I can’t be any clearer in my wrongness.)

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andrew 01.23.04 at 7:49 am

I wonder how the shifts in the candidates’ prices after the first primary compare to shifts in stock prices after earnings reports.

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James Surowiecki 01.23.04 at 7:50 am

The point about the investors who know everything about one stock and nothing about 499 is a good one. But that’s what’s interesting, that people don’t invest only in the stocks that they really have superior information about(otherwise more money managers would outperform the market). And that suggests to me that in most cases people don’t know what they know and, just as important, don’t know what they don’t know (acknowledging, of course, that putting all your money into one stock, no matter how certain you were of it, would not be a sound investment strategy).

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Sebastian Holsclaw 01.23.04 at 5:07 pm

And that suggests to me that in most cases people don’t know what they know and, just as important, don’t know what they don’t know (acknowledging, of course, that putting all your money into one stock, no matter how certain you were of it, would not be a sound investment strategy).

Which brings us back to the market. Individuals don’t know enough about lots of things. But collectively The People do know enough and signal all sorts of knowledge through the markets.

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dsquared 01.23.04 at 6:35 pm

James: I would say that if someone is not “literally” making a decision, then they’re not “effectively” making it, when the context is buying and selling. It’s not that you don’t have a point, it’s just that the point is dependent on a sense of “cause” which is just too rarified. As far as I can see, one could argue analogously to your above that the people of Iraq were responsible for keeping Saddam Hussein in power by “not rebelling”. Which in a sense they were, but not one which ought to gain any traction.

Furthermore, does this mean that people with no holdings of stock at all are helping to set the price by “not buying”? How about people with no wealth at all who exercise the choice not to take out a bank loan or sell their house to buy stock? It strikes me that as yet undiscovered Amazon Indians might be part of the price discovery process on this basis.

Have you read Fischer Black on “Noise”, by the way? Not that it’s relevant to this point, but it’s a good piece.

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James Surowiecki 01.23.04 at 8:17 pm

Daniel, the question of who constitutes the “group of price-setters,” as it were, is a crucial one, and one that I haven’t answered in a way I’m fully happy with. I’d say it’s somewhere between Steve Ross on the one hand and the Amazon Indians on the other. More seriously, I think at the very least the group of price-setters for an individual stock has to include all the people who currently own the stock, and I think it should probably also include also those who are contemplating buying it. (Some economist, whose name I can’t remember, has an interesting, if maybe obvious, piece about how money managers give different stocks different levels of attention, so that there are those stocks they own, those they’re actively following, those they’re paying attention to in a loose way, and then those that they’re paying no attention to at all. I think anyone who’s doing one of the first two things belongs in the group, and maybe people who are doing the third do as well.)

I agree that this requires a different sense of “cause” than most economists use, but I don’t think it’s so rarified (at least not if you delineate the group carefully enough) as to be wrong or useless. The difference for me between investors in a stock and the Iraqi people is that there’s an enormous cost to trying to overthrow Saddam, so that the lack of a rebellion doesn’t prove anything about what the Iraqis really wanted. There’s no cost — practically speaking — to selling a stock you already own, and only minor costs to buying one (assuming a boundedly rational person would only buy a stock they’re already paying attention to). So if you don’t sell, or don’t buy, I’m comfortable saying that you’re making a judgment on the value of the stock, just as much as if you do buy or do sell.

Along these lines, I’ve always found it curious that the advocates of the marginal-investor theory say that the marginal “buyer” is the one setting the price. There’s obviously someone on the other side of the trade, so why don’t we say it’s the marginal “seller” who’s setting the price? I think the reason is that in the original CAPM, supply is assumed to be fixed and inelastic. But this seems just wrong as a description of how prices are set. I think the demand curve for stocks slopes downward and the supply curve — which in this case represents the shares that existing shareholders will sell –slopes upward. And the curves are aggregate, not individual, I think, the way they are in any one-price market.

“Noise” is a very good piece. Shallowly, I like the fact that it’s readable and clear.

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