Talk:Prediction market

message: (Note to future editors:  Please distinguish between a public fact and a rumor.)
Sholdn't http://guaranteedweather.com/ be listed on this page?
I found this anonymous comment inappropriately added to the article, so I put it here.
--babbage 10:21, 12 Dec 2004 (UTC)
thread_title: Note to editors

message: Someone has disputed that Owise belongs on this page.
How is Owise.com less of a prediction market than Newsfutures? Sure Owise uses a fake ranks, and Newsfutures uses fake money, but what's the difference, really?
If you want to limit this page to only real-money systems, Newsfutures should also be removed.
: The Owise site is explicit that it is not a prediction market . It's something else, possibly fitting better in some Collaborative filtering area.  —Preceding unsigned comment added by Cretog8 (talk • contribs) 05:17, 12 June 2008 (UTC)
thread_title: Owise

message: I think it would be helpful to have a new page called "List of prediction markets" or something similar, much like the current List of spreadsheets and List of word processors (among others); the "external links" section is getting a little cluttered. Or maybe it would be even better to have two new pages, "List of prediction market exchanges" and "List of prediction market software", since the two are for the most part distinct. Does anyone else have an opinion on this? Yaron K. 20:44, 7 December 2006 (UTC)
replies: text: See :Category:Prediction markets. — Swpbtalk.edits 17:51, 4 January 2008 (UTC)
thread_title:  New "list" article(s) needed? 

message: The University of Iowa has a new prediction market to forecast infecteous diseases, especially flu.  This seems like an application worth mentioning in this article.  The website is: http://fluprediction.uiowa.edu/fluhome/index.html.  --Benstrider 23:36, 1 March 2007 (UTC)
thread_title: Iowa Health Prediction  Market

message: removed section per Wikipedia is not a directory. Wikipedia is not a repository for lists,  directories or Advocacy of commercial products and/or websites. NPOV requires views to be represented without bias, this applies not only to article text, but to companies, company lists, products, external links, or any other material as well.--Hu12 00:23, 4 May 2007 (UTC)
thread_title: removed section

message: Entire concept is flawed. Insider trading, manipulation. No SEC equivalent. Market prices in such would reflect likely futures about as well as current stock prices reflect company quality, that is, not at all.
:Its not. Brusegadi (talk) 04:56, 12 June 2008 (UTC)
replies: text: The only way insider traders could make money would be by increasing the accuracy of the prediction.  75.61.102.8 (talk) 04:44, 12 June 2008 (UTC)

text: Apart from the possibility of allowing such strategies, if you have enough players, thats too expensive.  People will make money off you.  Brusegadi (talk) 23:37, 13 June 2008 (UTC)

text: I find it hilarious that in your attempt to criticize prediction markets, your example actually increases the accuracy of the market! --Gwern  (contribs) 16:15 15 August 2011 (GMT)
It's not flawed it's just early in it's application to the internet, the concept is as old as the trading itself. 136.206.222.20 (talk) 14:06, 15 August 2011 (UTC)
thread_title:  Flawed 

message: Note to editors: Footnotes go after punctuation. --JHP 06:30, 1 September 2007 (UTC)
thread_title: Footnotes go ''after'' punctuation

message: The article claims
:Notable exceptions are Intrade/TradeSports, which escapes U.S. legal restrictions by operating from Dublin, Ireland, where gambling is legal and regulated,
without supporting that statement with a reference. Intrade's own FAQ specifically refuses to answer the legality question . Further the given rationale does not hold water: just because a betting site operates legally in its country does not mean that it can legally offer betting services to U.S. residents or that U.S. residents can legally gamble on the site. AxelBoldt (talk) 21:39, 7 February 2008 (UTC)
thread_title:  Legality of InTrade in U.S.? 

message: Does anyone suppose that the external links should be to actual prediction markets instead of web sites about them? I was sure, given my experience with Wikipedia, that this article would link to some primary sources. Certainly the secondary sources have academic merit, but please keep the reader in mind:  Which links will serve the greater number of readers? 
And yes, I am familiar with WP:EL.  I'm not familiar with anything in it that would preclude helpful links to primary sources, because if there is, I am sure that WP:IAR, which which I am also familiar, would preempt it. 75.61.102.8 (talk) 04:49, 12 June 2008 (UTC)
thread_title:  External links stand to be improved 

message: The "Related prediction methods" section seems unnecessary to me as a whole. Of course there's other ways of trying to aggregate information for predictions, but unless it can relate very directly to prediction markets, it seems like stuff for other articles. Cretog8 (talk) 05:21, 12 June 2008 (UTC)
replies: text: I removed the section. In case someone wants to work with the material to include in other articles, I've put it (for now) on my Scratchpad.Cretog8 (talk) 18:37, 20 June 2008 (UTC)
thread_title:  Related prediction methods 

message: In the last revision I edited, I found duplicate named references, i.e. references sharing the same name, but not having the same content. Please check them, as I am not able to fix them automatically :) 
* "pmdmm" :
** "Prediction Markets: Does Money Matter?" Servan-Schreiber (Electronic Markets, 2004)
**  "Prediction Markets: Does Money Matter?" Servan-Schreiber (Electronic Markets, 2004)
DumZiBoT (talk) 02:48, 9 August 2008 (UTC)
thread_title:  Bot report : Found duplicate references ! 

message: :Hollywood Stock Exchange creator Max Keiser suggests that not only are these markets no more predictive than their established counterparts such as the New York Stock Exchange and the London Stock Exchange, but that reducing the unpredictability of markets would mean reducing risk and, therefore, reducing the amount of speculative capital needed to keep markets open and liquid.
The first part of this paragraph claims that these markets are no more predictive and the rest of it describes the advantages of being more predictive. This doesn't sound right. Since no source is given, it is not possible to check the paragraph and I removed it. 
The original Version added by an anonymous writer was quite different but also unsourced. 
:Adding to the chorus of those who question the powers of markets to predict outcomes is Hollywood Stock Exchange creator, Max Keiser, who, summing up his views in a letter published in the Financial Times suggests that not only are these markets no more predictive than their established counterparts, such as the New York Stock Exchange and the London Stock Exchange, but that if markets could predict outcomes then it would no longer be capitalism. Reducing unpredictability of markets through predictability of outcomes would mean reducing risk and, therefore, reducing the amount of speculative capital lost and that is needed to keep these markets open and liquid.
78.48.176.195 (talk) 11:07, 7 March 2009 (UTC)
replies: text: Refs: FT letter; mirror. For those interested in market manipulation, Hanson has already addressed the topic. --Gwern  (contribs) 16:39 7 March 2009 (GMT)
History section makes some impressive claims for Hollywood stock exchange but does not give any source for these - unless these claims can be given a valid source then they seem like opinion  — Preceding unsigned comment added by 78.149.205.94 (talk) 23:20, 4 November 2012 (UTC)
thread_title:  Max Keiser 

message: Broken link in 10th reference  —Preceding unsigned comment added by 212.192.248.201 (talk) 13:55, 12 December 2010 (UTC)
replies: text: Thanks for pointing it out. Replaced it with a working link. --Ronz (talk) 17:07, 12 December 2010 (UTC)
replies: text: This domain is now for sale, so this link should be removed J.malczewsky (talk) 14:03, 8 May 2021 (UTC)
thread_title:  Broken link 

message: I propose that Prediction Market be merged into Betting Exchange. I think that the content in the Prediction Market article can easily be explained in the context of Betting Exchange. Betting exchanges and prediction markets are synonyms. It's confusing to the public to use both terms. The application of a PM/BE can be tweaked to different contexts, but it's essentially the same thing. Jasontrost (talk) 22:45, 1 June 2015 (UTC)
thread_title:  Merger proposal 

message: I want to write a new section (or paragraph) on combinatorial prediction markets, where you can make bets that are conditional on other contracts/outcomes. Does that sound fine to anyone watching this article? Ted Sanders (talk) 00:21, 17 July 2015 (UTC)
thread_title:  New section on combinatorial prediction markets 

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thread_title:  External links modified 

message: The article has no mention of sports betting which is way bigger than the sorts of things discussed here. The definition given is "are open markets that enable the prediction of specific outcomes using financial incentives". I find it hard to see how sports betting sites are not an example that fits perfectly into this definition. There seems some opinions given here that purpose of sports betting is for gambling whereas prediction markets have some more noble purpose of getting a better prediction. However if you want 'a better prediction' of a sports event outcome what do you do other than looking at bookie odds? It seems a perfect example to me but there seems disagreement.
I think this should be dealt with in the article by saying whether or not sports betting is an example or why this might be considered controversial rather than not mentioning sport betting at all. C-randles (talk) 05:21, 25 November 2023 (UTC)
replies: text: Some prediction markets do include sports, so they certainly should not be excluded. The article definitely should not contain editorializing about the subject, as was just added. The difference between the two is that 'odds' on prediction markets are crowdsourced, set by market pressures as in the stock market, not selected by some private means by a bookie. MrOllie (talk) 15:50, 25 November 2023 (UTC)
replies: text: Thank you for the comment and explanation. I thought there was disagreement with examples on this talk page. So it needed a NPOV explanation and to explain what this article does. My attempt may well not be ideal for an introductory paragraph so if you see a better way to meet the aims please have a go. I disagree re bookie using some private means, the weight of value bet changes the odds offered in an identical manner to a stock exchange or prediction market. Even if you believe there is some difference here, both are a form of aggregation of many peoples views and the more that a person bets the more it changes the odds to find some aggregated average expectation. Now we have another example of people disagreeing on whether there is a difference. = More need to explain. C-randles (talk) 16:04, 25 November 2023 (UTC)
replies: text: 'Bookie' odds change, but are indeed set by a private formula - the odds aren't even before anybody places a bet, for example. MrOllie (talk) 16:10, 25 November 2023 (UTC)
replies: text: A stockmarket, market-maker has exactly the same sort of private formula. So can a prediction market market-maker. If someone setting up a prediction market want to leave the odds at even when it starts they can, or they can make sure they are first to bet so that for anyone else coming to the market the odds are not even to starts or maybe a prediction market could allow this to be private. These arguments are easily rebutted. C-randles (talk) 16:32, 25 November 2023 (UTC)

text: We're getting into WP:NOTFORUM territory. If you have a reliable source to present that explains any differences (or that claims they are the same thing), feel free to present it and perhaps something can be added to the article. MrOllie (talk) 16:52, 25 November 2023 (UTC)
replies: text: PS: On Wikipedia, most lists are kept to notable entries only. Which means WP:N here - it is shorthand for 'has a preexisting Wikipedia article'. This kind of restriction is necessary to keep lists from promoting obscure websites. Restoring stuff that has been judged to be nonnotable (for example by being deleted at a WP:AFD discussion) is particularly bad. MrOllie (talk) 16:56, 25 November 2023 (UTC)

text: I don't think that quote supports your text exactly. But I think the article could say something similar. Instead of focusing on an individual talk about the aggregate, which is what the source describes. I would summarize it with something like "When the group is more optimistic they will 'bet' more in aggregate than the pessimists, raising the market price. The movement of the price will reflect more information than a simple average or vote count." MrOllie (talk) 20:29, 25 November 2023 (UTC)

text: Who is defining the scope to exclude sport betting? What do the reliable sources on this topic say? MrOllie (talk) 23:21, 25 November 2023 (UTC)
replies: text: Searching the scientific literature would be time consuming because there is so much of it and I suspect most researchers are enthusiastic about prediction markets so if they have the choice researchers mostly want to talk about markets where the information extracted could be considered more useful rather than just a better assessment of a particular sports outcome. Making the research about that would seem like it is gambling that is bad so they prefer to do research on election betting and similar. So it may well be difficult to find research saying whether sports betting is an example or not. Anyway to attempt a search of the literature I tried
quote:
From the scientific literature on prediction markets only, do researchers think sports betting is an example of a prediction market?
ChatGPT answer:
Prediction markets and sports betting share similarities, but they are distinct concepts with different purposes and characteristics. While both involve making predictions about future events and have an element of risk, their underlying mechanisms, goals, and structures can differ significantly.
Prediction markets are often designed to aggregate and reflect the collective wisdom or information of a group of participants regarding the likelihood of specific future events. They are used in various domains, including finance, politics, and technology. Participants trade contracts representing different outcomes, and prices of these contracts are determined by the market based on the perceived probability of each outcome.
In contrast, sports betting typically involves individuals placing wagers on the outcome of sporting events. The odds set by bookmakers reflect their assessment of the probability of different outcomes, but these odds may also be influenced by factors such as the betting behavior of participants and the bookmaker's profit margin.
In the scientific literature on prediction markets, researchers may recognize sports betting as a form of prediction market, albeit one with unique characteristics. Some may emphasize the differences between traditional prediction markets and sports betting due to factors like bookmaker margins, the role of chance in sports outcomes, and the influence of public sentiment on odds.
It's important to note that the terminology and perspectives on these topics can vary among researchers, and the field evolves over time. If you're interested in the most up-to-date and nuanced perspectives, it's recommended to consult recent scientific literature or experts in the field.
/quote
So I think I should accept there may well be justification for keeping this page mainly about useful information oriented markets with limited reference to sport betting. C-randles (talk) 12:38, 26 November 2023 (UTC)
thread_title:  Sports betting - an example or not? 

message: 0 to 100% is typical but is not always the case. I gave example in edit comment
There certainly are other types for example https://manifold.markets/tailcalled/how-much-will-the-eu-spend-on-milit-feebc6ba48bd
So this was an error correction to the article not editorialising. Perhaps you would care to revert your revert? C-randles (talk) 17:06, 25 November 2023 (UTC)
replies: text: If you want to change the article lead, bring reliable sources, and start by adding sourced content to the article body. A link to a question on one of the markets in an edit summary is not sufficient. MrOllie (talk) 17:14, 25 November 2023 (UTC)
replies: text:  So you prefer obvious errors to be left in the article? You could admit that I did not add back the editorialising you originally complained of, I am happy to let that discussion continue before attempting any further edit in that vein. Here I thought it was so obviously incorrect that it didn't need a reference or example in the article. Maybe tomorrow when it isn't breaking 1R I will try again. C-randles (talk) 17:22, 25 November 2023 (UTC)
replies: text: I prefer that core policies such as WP:V and WP:NOR be followed. MrOllie (talk) 17:24, 25 November 2023 (UTC)
thread_title:  I don't want to edit war but 0 to 100% is blatently not always the case 

message: Currently the "accuracy" section is too long and unstructured to give a useful overview of the accuracy of prediction markets. Different paragraphs contain contradictory information, with some claiming in a overgeneralized way that prediction markets yield accurate predictions and some claiming that prediction markets fail to make good predictions. In my view, the section currently contains, in disordered manner, content on three subsections: 1. The theoretical basis for predictions markets: Efficient market hypothesis, traders being able to quantify the strength of their belief. 2. Overview of empirical evidence that prediction markets are good at summarizing the opinion of the market participants, as well as how they compare to polls and other methods of opinion aggregation (including that polling with belief strength quantification can beat prediction markets). One can also mention arbitrage opportunities between prediction markets here. 3. Overview of empirical evidence on how the summarized opinion of market participants may be biased because of insufficient information, missing specialized knowledge, and cognitive biases such as the "50% bias".
The section should be restructured to present information on these 3 topics in a clear way. --Maximilian Janisch (talk) 16:52, 11 February 2024 (UTC)
thread_title:  Accuracy section should be restructured