Talk:Prediction market

Note to editors

(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)

Owise

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 [1]. 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)

New "list" article(s) needed?

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)

See Category:Prediction markets. — Swpb^talk.edits 17:51, 4 January 2008 (UTC)

Iowa Health Prediction Market

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)

removed section

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)

Flawed

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)

- Why is the PM concept flawed? Do you have any evidence that supports this? —Preceding unsigned comment added by 129.240.70.150 (talk) 13:05, 8 September 2007 (UTC)

-- It doesn't matter if the concept is flawed, merely that it is an important enough concept, or is used by enough people, for a Wikipedia entry. After all Intelligent Design is a deeply flawed concept (i.e. it is wrong) and yet there is a large and often edited article on it... Duncan 10:57, 22 October 2007 (UTC)

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)

- Incorrect. An insider could short sell, then deliberately sabotage the outcome of an event. —Preceding unsigned comment added by 216.12.8.141 (talk) 17:11, 13 June 2008 (UTC)

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)

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)

Footnotes go after punctuation

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

Legality of InTrade in U.S.?

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 [2]. 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)

Until someone can find more reliable citations, I recommend (and plan on) adding a comment that it's unknown whether the rationale means that US residents can legally use Intrade. JustinBlank (talk) 01:12, 3 September 2008 (UTC)

The wording is ambiguous, not necessarily incorrect, it should probably be more explicit. Intrade is allowed to operate because it is in Ireland. Thus Intrade itself avoids prosecution by US authorities. This does not mean people in the US are allowed to place bets without breaking US law though. The CEO of Intrade has said in correspondence with US authorities that he is unsure where he stands under US law. 129.170.66.218 (talk) 09:44, 7 September 2008 (UTC)

Prediction market vs. futures market

I'd like to see this article explain the difference between a prediction market and a futures market. --JHP (talk) 01:08, 30 May 2008 (UTC)

The factors underlying a prediction market are the outcomes of specified events. Underlying a futures market, on the other hand, are the prices of commodities, stocks and their indices. 75.61.102.8 (talk) 04:47, 12 June 2008 (UTC)

According to "Business Dictionary" at {http://www.businessdictionary.com/definition/physical-market.html}, (1) a physical market is "a commodity market where purchasers actually buy the commodities, as opposed to the futures market, where they buy and sell the right to purchase commodities at a future date". The following words were underlined in the previous quote: market, purchasers, buy, commodities, futures market, sell, right, and purchase. Using the same source, (2) a futures market is a "Market in which participants can buy and sell commodities and their future delivery contracts. A futures market provides a medium for the complementary activities of hedging and speculation, necessary for dampening wild fluctuations in the prices caused by gluts and shortages." The following words were underlined in the previous quote: Market, participants, buy, sell, commodities, delivery, contracts, provides, activities, hedging, speculation, fluctuations, prices, gluts, and shortages. I claim without citation that in common American vernacular "Futures market" is heard on the news more often than "Prediction market". Does anyone dispute this claim or need citation from a scientific survey concerning what is common vernacular? I had never heard the term Prediction market used until I looked for the definition of futures market and this Prediction market Wikipedia article appeared as an option. Why is this article titled Prediction market instead of Futures market? Which of the two phrases, "predictive market" and "futures market" is more useful? I propose that this article's title be changed to "Futures market" unless there is a difference because of an English, the nation, difference or an objection that the phrase Prediction market is used more often in society than the phrase Futures market. Gauzeandchess (talk) 03:14, 7 February 2012 (UTC)

Er... what? You don't hear prediction market because prediction markets are currently banned in America with the exception of the tiny IEM. Even were they not banned, futures would still be far more common because countless businesses large & small would use them. So no, the name should not be changed. --Gwern (contribs) 15:05 7 February 2012 (GMT)

Is a prediction market the same as a futures market? I could not find a definition that makes a distinction between them at {http://www.querycat.com/question/afa3f14b02bf1b6450b5f6fccd9a2018}. A difference between the two markets could be at {http://bpp.wharton.upenn.edu/jwolfers/Papers/DoesMoneyMatter.pdf}, which stated a hypothetical prediction market contract might "pay $100 if George W. Bush is re-elected in 2004, or nothing if he is not. Thus, until the outcome is decided, the trading price reflects the traders’ collective consensus about the expected value of the contract, which in this case would be proportional to the probability of Bush’s re-election." How is this different than a futures market contract that stipulates a given product, such as wheat, will be sold at P price per volume if there is a drought or if there is a bounty, which itself is based upon the probability of a drought or bounty? Is there a small difference between the two markets? I would like to delete these questions and retract my previous suggestions for changes if there is a difference. Gauzeandchess (talk) 06:17, 9 February 2012 (UTC)

What commodity are you buying on a prediction market? How many GWB shares must I buy to get delivery of a pork belly or an ounce of silver in November 2004? --Gwern (contribs) 15:03 9 February 2012 (GMT)

I infer by your question that you claim there is a difference between a prediction market and a futures market wherein one could not purchase a product or service in a prediction market, such as GWB (Great Western Broadcasting or Gypsum Wall Board) pork shares whereas one could purchase a product or service, such as GWB pork shares in a futures market? If my inferred statement represents your claim for a difference between a prediction market and a futures market, then could you please cite an academic text that also supports this claim? Does a prediction market contract cover the following hypothetical? I sign a contract purchasing S shares of pork for D dollars to be delivered at future T time unless there is an increased pork price from an increased fuel price, which stipulates that the cost would be D + 1 regardless of the increased pork price. If this hypothetical contract is a prediction market contract and is a futures market contract, then is there a difference between the two market types? What is the difference between a prediction market contract and a futures market contract? A futures market contract is a transfer of possession of something. And in this hypothetical, a prediction market contract took possession of something. Is this not the case for a prediction market? It is difficult for me to understand the difference between the two market types because I cannot find much about the difference from doing internet research or find out much about the difference based on your question "What commodity are you buying on a prediction market?". In answer to your question, firstly I don't know the answer to your question because I don't know what a prediction market is, hence my questions about this topic, other than the stipulation about a money exchange when some future event occurs, secondly, I described a hypothetical scenario where a prediction market contract took possession of pork that would have an exchange of money in the future if some future event occurred. Does this type of contract occur in a futures market? I didn't know what GWB stood for and found two likely meanings at "http://www.abbreviations.com/GWB". Gauzeandchess (talk) 09:51, 14 February 2012 (UTC)

Let me take a shot at this. When one buys a security in a prediction market, what one is buying is a payout if a particular verifiable future condition turns out to be true. Suppose I think that the likelihood of a particular candidate winning an election is 70%. Then, I should be willing to pay up to 70 cents for a security that issues a dollar if that event is true (and sell securities that pay more than 30 cents for another candidate). Who would issue such a security? One example is an individual who could make a larger amount of money off of a given bit of information, doesn't know it, and wants to elicit the information from a different group who may know, but doesn't trust their opinion. The prediction market is thus a particular kind of futures market where predictions and money are the only commodities changing hands. It is certainly possible to make a prediction market security that refers to a futures market (this asset pays out $1 if the price of corn is greater than X at time T according to so-and-so). Note that I don't actually buy or sell any corn: it's a side-bet. John b cassel (talk) 13:37, 18 February 2012 (UTC)

External links stand to be improved

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)

Related prediction methods

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)

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)

Bot report : Found duplicate references !

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" :
  • [http://www.newsfutures.com/pdf/Does_money_matter.pdf "Prediction Markets: Does Money Matter?"] Servan-Schreiber (Electronic Markets, 2004)
  • [http://www.newsfutures.com/pdf/Does_money_matter.pdf "Prediction Markets: Does Money Matter?"] Servan-Schreiber (Electronic Markets, 2004)

DumZiBoT (talk) 02:48, 9 August 2008 (UTC)

Max Keiser

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)

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)

Broken link

Broken link in 10th reference —Preceding unsigned comment added by 212.192.248.201 (talk) 13:55, 12 December 2010 (UTC)

Thanks for pointing it out. Replaced it with a working link. --Ronz (talk) 17:07, 12 December 2010 (UTC)

This domain is now for sale, so this link should be removed J.malczewsky (talk) 14:03, 8 May 2021 (UTC)

Merger proposal

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)

completely disagree that a prediction market is synonymous with a betting exchange..betting exchanges are for gambling and trying to profit from same whether by skill or chance...prediction markets are for predictions with the added rigor of consequences from financial gain or loss as opposed to opinions... — Preceding unsigned comment added by 193.120.22.171 (talk) 08:23, 2 June 2015 (UTC)

The types of traders that trade on prediction markets and betting exchanges are the same because they contracts that are designed the same. Both are binary options traded around an event, sports, elections, award shows, etc. Indeed most betting exchanges offer trading on non-sports contracts. Betting exchanges have been marketed to sports bettors and prediction markets have been marketed to financial types, but the math is the same, the people trading in both want to maximize profitJasontrost (talk) 15:42, 27 July 2015 (UTC)

New section on combinatorial prediction markets

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)

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Kalshi

Hello! As of November 2020, the Commodity Futures Trading Commission granted Kalshi approval as the first federally regulated designated contract market (DCM) for event contracts. It may be worth seeing if we could add Kalshi to this article as the next step forward in for prediction markets. Source: https://www.cftc.gov/PressRoom/PressReleases/8302-20. Kalshi's website: https://kalshi.com. Note: I am affiliated with Kalshi and will not make these edits, but here are some suggestions:

• Under "Milestones in development of modern electronic prediction markets" --> Kalshi is the first federally regulated exchange for event contracts
• Under "Legality" --> Kalshi is directly regulated by the CFTC and is completely legal
• Under "Public prediction markets" --> we could add Kalshi here

Kamyarghiam-kalshi (talk) 21:00, 20 October 2021 (UTC)

I don't think the claim of 'first' is accurate, binary options have been available in US regulated markets since at least 2008. Are you sure you want your company mentioned on Wikipedia? Any discussion of Event Contracts or companies who deal in them is inevitably going to have to mention the extensive history of fraud that has gone on in that industry. MrOllie (talk) 12:13, 22 October 2021 (UTC)

Hi again @MrOllie:

Please see https://en.wikipedia.org/wiki/Talk:Futures_exchange#Kalshi for my reply regarding the "first" claim. Regarding the extensive history of fraud: yes, if that is the history of the industry, then it should be recorded here. In fact, it shows the importance of federal regulation in this industry. We are trying to work closely with regulators to make sure investors feel confident and safe trading on our exchange. For the record, I'd like to note my affiliation with Kalshi: I am a paid full-time software engineer for Kalshi. I am currently working on providing accurate information for Kalshi online. Kamyarghiam-kalshi (talk) 17:26, 22 October 2021 (UTC)

Sports betting - an example or not?

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)

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)

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)

'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)

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)

Perhaps a more standard argument for why they are different: from elsewhere somebody said "I think that being intended to create accurate forecasts rather than just provide a place to gamble is indeed the thing that distinguishes prediction markets from gambling sites." to which I replied And the reality that the two things essentially do exactly the same thing, attracts the same sorts of people or at least there is a large overlap, that it potentially has the same benefits of getting better predictions and the same drawbacks of potential causing addiction/spending too much time and/or money than is sensible or healthy for some participants .... are just inconvenient facts that shouldn't get in the way of the opinion you are stating? C-randles (talk) 16:37, 25 November 2023 (UTC)

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)

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)

I have added "Markets tend to perform better than polling.[ref see link below] When market participants have some intrinsic interest in trying to predict results, even markets with modest incentives or no incentives have been shown to be effective." I really want to add more along the lines of: the more sure a person is of their belief the more that they will be willing to bet. Therefore the market price combines this extra information on how sure a person is in its average market price in a way that polling does not. The best ref I have found for this is "traders may be working with more information than poll respondents. Further, prediction markets aggregate opinions in a unique way. The market price is the point at which optimistic and pessimistic opinions “cross”. The market price is thus a marginal opinion that is not simply an average or a vote count" from [3] is that adequate or am I still editorialising? C-randles (talk) 20:19, 25 November 2023 (UTC)

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)

I presume that The_Wisdom_of_Crowds#Prediction_markets should be a summary of what is here. However it seems quite different for example including "Betfair is the world's biggest prediction exchange, with around $28 billion traded in 2007." The content seems quite different and we need to define the scope of this article as to whether it includes sports betting. This seems to hit disagreements on whether sports betting is an example. I think the market mechanism is important as discussed above, same ref continues "It could be that the magic of prediction markets lies largely in superior aggregation methods rather than superior quality or informativeness of responses.". If the refs are saying the market mechanisms are important then sport betting which include market mechanisms and it seems strange to me to define the scope to exclude sport betting. If I don't know which way this scope discussion is going to go, then it seems hard to work on improving the article efficiently, so thoughts and different views on whether and how to include sport betting would be appreciated. C-randles (talk) 21:31, 25 November 2023 (UTC)

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)

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)

I don't want to edit war but 0 to 100% is blatently not always the case

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)

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)

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)

I prefer that core policies such as WP:V and WP:NOR be followed. MrOllie (talk) 17:24, 25 November 2023 (UTC)

The article includes "ability to make numeric-range or date-range predictions" so the lead is contradicting the article by suggesting all contracts are 0% to 100%. If this is already in the article then the lead should summarize correctly, not do its own wrong thing. C-randles (talk) 20:56, 25 November 2023 (UTC)

Accuracy section should be restructured

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)