lunedì 15 giugno 2020
BATTAGLIE PER LA DESTRA: PIU' RISULTATI, MENO PROCEDURE.
lunedì 8 giugno 2020
PERCHE' NON MI FIDO DELLA SCIENZA.
https://feedly.com/i/entry/pCjzw1s9uw4o7o2a6k88mWl61VH8mv6Frk5BTARJuI0=_172811114c1:1690f49:7f9fc8a1
https://twitter.com/sullydish/status/1268315812009594882
giovedì 27 febbraio 2020
CAPUA vs BURIONI
martedì 1 ottobre 2019
VOTARE GUADAGNANDOCI
mercoledì 29 maggio 2019
F scommesse
http://www.overcomingbias.com/2019/05/understandable-social-systems.html
A che serve un prediction market?
YouNow
Alternative: maggioranza, prestigio, dominanza
venerdì 26 ottobre 2018
Scommettere sulla qualità
Di solito la qualità di un lavoro scientifico viene affidata alle citazioni che riceve. Non esiste qualcosa di meglio? Forse sì.
He focused on papers for which it is possible to make a replication attempt and said “We don’t need journals anymore.” That is, he argued that we should not use which journal is willing to publish a paper as a signal of paper quality, but that we should use the signal of what bet authors offer in support of their paper.
That author betting offer would specify what would count as a replication attempt, and as a successful replication, and include an escrowed amount of cash and betting odds which set the amount a challenger must put up to try to win that escrowed amount. If the replication fails, the challenger wins these two amounts minus the cost of doing a replication attempt; if not the authors win that amount.
Bets As Signals of Article Quality http://www.overcomingbias.com/2018/10/bets-as-signals-of-article-quality.html
venerdì 26 maggio 2017
La scommessa come bussola
… The human part of any large intelligent system is by far the most intelligent part. As long as this remains true, the biggest system advancements will come from aids that fill big holes in human abilities, rather than from artifacts that stretch engineers' abilities. Consider Post-it Notes or, better yet, plain paper notepads. These probably seemed like trivial ideas, but they turned out to be terribly useful…
… Consider, for example, a clearly important policy question such as, How would crime rates change if more citizens could legally carry hidden guns?… I suspect that the existence of such divergent opinions reflects the fact that we suffer from a serious failure to share information… The real problem is not finding more words, but judging who really knows about the topic and whether these experts are saying what they know. We are in many ways bit-full, yet information-poor…
… I suggest that speculative markets are a neglected way to help us find out what people know. Such markets pool the information that is known… Speculative markets are decentralized and relatively egalitarian, and they can offer direct, concise, timely, and precise estimates in answer to questions we pose. These estimates are self-consistent across a wide range of issues and respond quickly to new information. They also seem to be cheap and relatively accurate…
… Imagine that we created markets where people could bet on future crime rates, conditional on allowing or not allowing more hidden guns. That is, if the market prices predicted that murder rates would be 10 percent higher should a certain hidden-gun bill pass, then anyone who thought this estimate too high could easily identify a particular profitable trade… if market prices said that crime rates would be 10 percent higher given more hidden guns, most nonexperts would accept this estimate as our "best answer" or as a neutral "consensus."…
… Speculators, in turn, would have a clear incentive to be careful and honest in contributing what they know and in judging what advocates know… speculators must "put their money where their mouth is."
… Next, you must choose some particular trusted third party who will finally declare a murder rate M within [0,1] and determine whether bill B passed…
… Finally, you have to decide how much to subsidize this market. If interest in your topic is strong enough, simply creating these markets might induce people to trade in them. Failing that, sufficient interest might be induced if someone committed to make a policy choice based on the market estimate… You can also safely and directly subsidize a market to induce more participation…
… Murder rates-with or without capital punishment? • Average mortality rates-with or without national health insurance? • Health-care spending-with expanded or curtailed use of health maintenance organizations? • Employment change-raise minimum wage or rescind NAFTA? • Global sea-level and temperature changes-impose or not impose a carbon dioxide tax? • Military casualties-with a Republican or a Democratic president? • Stock prices-with a Republican- or Democrat-controlled U.S. Congress? • World per capita food consumption-raise or lower average tariffs? • Student test scores-with or without school choice or voucher reform? • Future national economic growth-raise or lower interest rates, or with or without an education subsidy?…
… decades of research on the efficiency of financial markets have found little price-relevant information that is not reflected in market prices… Any inefficiencies seem to be weak and to go away with publicity, because they represent a profit opportunity. If you think the current price is too low, you expect to profit by buying now and selling later, and buying now will raise the price… For example, orange juice futures prices have been shown to improve on government weather forecasts… Also, markets where traders can bet on election results predict vote totals better than opinion polls…
… while most traders tended to suffer from cognitive biases such as expecting others to agree with them, the most active traders were not biased this way-and active traders set the prices. Speculative markets thus seem to induce the real experts to self-select and participate more…
… Older economics writings sometimes give the impression that speculative markets will not function unless you have thousands of traders frequently trading millions of dollars worth of goods. Recent Web markets, however, clearly show that markets can be much smaller and slower than this…
… Until the last few centuries, the cost of simply handling trades was enough to sharply limit the number of speculative markets that could be made widely available. Yet today, ebay.com routinely sells $10 items by having a handful of people bid a few times each over a period of a week… More important, most speculative markets are now illegal. The short history of financial market regulation is that everything was once illegal until limited exemptions were granted for specific purposes… Gradually, exceptions were granted for what came to be seen as worthy purposes, such as teaching people about horses (horseracing) or raising state revenue (lotteries)… Stocks were allowed for the purpose of capitalizing firms… insurance was allowed to let individuals hedge risks… commodity futures and financial derivatives were allowed to let firms hedge more risks…
… how can we test prototypes if IA markets are generally illegal? Well, there is one plausible loophole (besides offshore gambling), which I have saved for those of you who are still reading this far: internal corporate markets…
… several companies, including Hewlett-Packard and Siemens, have begun experimenting with real-money internal speculative markets for estimating things such as future sales…
giovedì 15 dicembre 2016
La cattiva reputazione delle scommesse
… we could attend less to “hedgehogs” who know “one big thing” and whose forecasts are “beaten rather soundly even by the [random] chimp.”… hedgehogs, who focus on one main analytical tool, are less accurate than foxes, who used a wide assortment of analytical tools
… Some even persist in using forecasts that are manifestly unreliable…
… when I try to sell firms on internal prediction markets wherein employees forecast things like sales and project completion dates, such firms usually don’t doubt my claims that such forecasts are cheap and more accurate. Nevertheless, they usually aren’t interested…
… Media consumers can be educated and entertained by clever, witty, but accessible commentary…
… public want… to signal that they are smart and well-read by quoting and discussing the words of the same few focal pundits…
… Academics are primarily selected and rewarded for their impressive mastery and application of difficult academic tools and methods…
… By being personally impressive, and by being identified with attractive philosophical positions, leaders can inspire people to work for and affiliate with their organizations…
… champions need to assemble supporting political coalitions to create and sustain large projects. As such coalitions are not lightly disbanded, they are reluctant to allow last minute forecast changes to threaten project support…
… there are cultures where few requests made of acquaintances are denied. Since it is rude to say “no” to a difficult request, people instead say “yes,” but then don’t actually deliver. In other cultures, it is worse to say “yes” but not deliver… The difference is less in the technology of remembering, and more in the social treatment of such memories…
… in some cultures people who schedule to meet at particular times actually show up over a wide range of surrounding times. While this might once have been reasonable given uncertain travel times and unreliable clocks, such practices continued long after these problems were solved. In other cultures, people show up close to scheduled meeting times, because observers remember and think less of those who are late…
… it isn’t enough to just have a way to remember behavior. A track record tech must be combined with a social equilibrium that punishes those with poor records…
… Today, the simplest way to create forecast track records that get attention and respect is by making bets…
… Anti-gambling laws now discourage such bets…
… It should be shameful to visibly disagree and yet evade a challenge…