Cornell Info Blogs

Interesting, Hinge uses the Gale-Shapley algorithm for their "daily match" recommendation. For those unaware, the algorithm solves the Stable Marriage problem: find a global set of matches, so that every person prefers their match over all other potential matches who would prefer them over their own match. https://blogs.cornell.edu/info2040/2021/09/30/hinge-and-its-implementa…

> refutation to the belief that the Nash equilibrium is best for everyone That's not the claim of the Nash equilibrium. The idea behind a Nash equilibrium is that there's no better -- not best -- strategy for anyone (if all strategies are known). You can trivially build a game where outcomes are pretty awful for somebody -- or everybody -- but not as awful as changing strategies. The Tragedy of the Commons isn't really game-theoretic (or a Nash equilibrium, for that matter[1]), but rather regarded as a public policy thought experiment. Ostrom's discussion on the Tragedy is from this latter point of view. [1] http://blogs.cornell.edu/info2040/2018/09/18/the-tragedy-of-the-common…

From what I understand, Game Theory is used in "mechanism design", or basically the design of auctions for things like the FCC spectrum auctions, or how facebook / google auction off ad slots. Not a mathematician so I don't have any great references, but a couple bits in the press about it: http://blogs.cornell.edu/info2040/2015/10/20/application-of-game-theor… https://www.wired.com/2015/09/facebook-doesnt-make-much-money-couldon-…

For people not aware of how computer chess engines work or what a tablebase is. TLDR: chess would be fully solved if there existed a 64-piece tablebase. These guys have done the chess world a massive favour by computing the most important subset of the 8-piece tablebase and making it available to the world. Long version: Chess engines normally work by doing a highly optimised search of the game tree to some depth, evaluating the board position in each state using some evaluation function and then propagating the evaluation backwards up the tree. Then it’s a matter of picking the moves that lead to the game trees with the most favourable board state assuming both opponents make the best possible moves from the current position. The strength of the engine depends on the available computation, the efficiency of any tree pruning you’re able to do and the accuracy of the evaluation function, which is always going to be somewhat subjective. However when “few enough” pieces remain on the board (in the endgame), the number of possible game states is small enough that it’s possible to brute force solve the game from each state by enumerating all possible moves and resulting states so as to find the absolute optimal move for any given board position. Looking up the evaluation and best possible move for a given state if you had done all this computation beforehand is obviously much more efficient and accurate than the tree-search minimax thing I described initially, and being able…

I'll see if I can't find a few of them so I can link them directly then. I certainly remember seeing a few. As for the chilling effects, the problem with these things has always been a low visibility problem since you have no direct reference to compare against. The nature is still an active area of research, the going understanding seems to be its a distortion of conformity to norms issue where views are distorted around actions you may signal under certain types of structures (uncertainty and ambiguity). All you may see locally is skewed activity such as lower activity or less or no discussion in the words (regardless of meaning context) of posts signaled negatively in this way, very little disagreement. You'd see more collective downvoting for neutral and any subjects related or touching on subjects signaled. Not enough for you to notice anything thought. In many respects it follows a similar structure in education and reeducation under Mao, called the hot-potato, Lifton covers the details. Objectively, you'd see higher downvotes, as well for anyone that did try to discuss these things, higher squelch marks, even neutral positions that may be tangentially related may lose speaking power/karma. Unless you are running statistical analysis on a basket of subjects with a solid baseline, you likely wouldn't notice a thing, and that's by structure, which is why its insidious. Certain structures of elements short circuit perception and take advantage of a psychological…

> I spent 10 years in mammography software, and I saw first hand how many outside factors can impact a physician's decision to biopsy or not a given artifact on an image. This is slightly tangential, but I'm curious about your perspective on a classic example of medical statistical illiteracy. Whenever surveyed, the strong majority of doctors vastly overestimate the odds of a true positive mammogram (half of them by a factor of 10!!), due to flawed Bayesian thinking and the low base rate of breast cancer.[1] Does your anecdotal experience contradict this data? If not, wouldn't two minutes of stats education (or a system that correctly accounted for base rate) utterly swamp intuition-driven analysis of tiny artifacts? Or is it simply that, through folk wisdom and experience, they implicitly adjust other terms in their mental calculus in order to account for this huge error in estimating one factor? [1] https://blogs.cornell.edu/info2040/2014/11/12/doctors-dont-know-bayes-…

I stand corrected: https://blogs.cornell.edu/info2040/2012/11/03/monkeys-and-information-…

There are multiple facets to the problem. Technical site performance is a very small part of those. The disruption, manipulation, and most of all erosion of trust which bad-faith actors create (AI or otherwise) are the most serious issues in my experience. The concept of "evaporative cooling", in which a platform starting to go bad sees an accelerated departure of well-intentioned, high-value participants. See the original article from 2010: <https://web.archive.org/web/20101012105003/https://blog.bumblebeelabs.… (HN discussion: <https://news.ycombinator.com/item?id=1777665>). And an interesting follow-up, 2015: <https://blogs.cornell.edu/info2040/2015/10/14/the-evaporative-cooling-… (HN discussion, from 2025: <https://news.ycombinator.com/item?id=42597962>).

Related: https://blogs.cornell.edu/info2040/2015/10/14/the-evaporative-cooling-…

Game Theory Optimal This page has more details: https://blogs.cornell.edu/info2040/2021/11/03/game-theory-optimal-gto-…

Please read the academic paper by Larry Page and Sergey Brin, available at this link: https://blogs.cornell.edu/info2040/2019/10/28/the-academic-paper-that-… You might find their perspective on advertising surprising. Returning to my earlier point, please expand your argument about why OpenAI may fail. Let’s aim to elevate the discussion.

The faster they grow, the sooner they hit the wall https://www.newyorker.com/culture/cultural-comment/chinas-involuted-ge… https://blogs.cornell.edu/info2040/2021/09/28/involution-neijuan-in-ch…

Reminds me of evolutionary stable strategies in game theory. In this case, the payoffs are even for two strategies in repeated games. There are also unstable games like this one: https://blogs.cornell.edu/info2040/2016/11/26/side-blotched-lizard-and…

Don't forget ten years of schooling to be bad at formal methods to step out of that decision tree: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9237793/ https://blogs.cornell.edu/info2040/2014/11/12/doctors-dont-know-bayes-… https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3016704/ https://www.overcomingbias.com/p/doctor-there-arhtml And many more. go to r/residency or other doctor forums if you want to see the most repugnant combination of dunning kruger and condescension

The Undercover Economist book mentions these. They're honest but they're publicly embarrassing for governments in auctions with few bidders, because sometimes there would only be two bidders, one bidding $100k and one bidding $4, so people were wondering why the winner who was only bidding $100k was only paying $4 for a license. [0] The book goes on to describe the UK 3G Telecom license auction[1] and explain how it went much better. [0]: https://blogs.cornell.edu/info2040/2022/10/31/when-an-auction-fails-ne… [1]: https://www.nuff.ox.ac.uk/economics/papers/2002/w4/biggest29nov.pdf

Mentioned in the post, Cornell provides some really cool interactive data: - fine grained map of the wages/% making livable wage: https://blogs.cornell.edu/livingwage/ - likelihood of making livable wage based on a multitude of configurable factors: https://blogs.cornell.edu/livingwage/calculate-probability-of-earning-…

Northwestern University uses (or used) a version of this for their basketball team, which they call "Purple Pricing". https://blogs.cornell.edu/info2040/2022/10/25/sports-ticket-pricing-du… https://hbr.org/2013/05/any-business-trying-to-sell

Not a sandwich but an equilibrium. What is it good for if there's no mechanism to reach it? "What they’ve found is that some games have Nash equilibria that are impossible for a computer to determine and even more equilibria are computable only if one of the largest open problems in computer science, P = NP, is solved." https://blogs.cornell.edu/info2040/2015/09/21/the-computability-of-nas…

This reminds me of https://blogs.cornell.edu/info2040/2015/09/17/transmission-a-game-abou… which was a lot of fun.

Here's an article for that: https://blogs.cornell.edu/info2040/2018/10/17/tian-jis-horse-racing-st…

I think strategically they should encourage their voters to support whichever major party supports electoral reform (adopting a voting system that doesn't have the spoiler effect), and only vote third party if neither of them do. In practice what this means is putting the Democrats on notice that they have to support RCV in every state, otherwise supporters of electoral reform will deliberately sabotage the party's chances and throw each election to the Republicans. This is from the "don't mess with me! I'm crazy enough to do it!" school of thought, which worked so well against the "split or steal" choice given in a famous quiz show clip.[0] That game was deliberately designed to be equivalent to the Prisoner's Dilemma, just as the US voting system ends up being. [0] https://blogs.cornell.edu/info2040/2012/09/21/split-or-steal-an-analys…

I wouldn't have a problem with a blind bid if we had second-price auctions. But that's unlikely. A tiny blog post about this: https://blogs.cornell.edu/info2040/2019/10/22/why-arent-homes-sold-in-…

Advertisers could pay to get unblocked. https://blogs.cornell.edu/info2040/2016/09/15/justin_kuang_adblock/

regarding “lemon” unit (i.e. faulty from the beginning). To be honest, I’m not quite sure where the term comes from. - It's origins are pretty interesting: https://blogs.cornell.edu/info2040/2016/12/02/origin-of-lemon-law/

Ticks are on all small mammals - field mice [1], rabbits, etc. Culling the deer won't be enough. [1] Check out these tick tubes: https://blogs.cornell.edu/nysipm/2019/06/28/dont-make-your-own-tick-tu…

Points for mentioning one of the few videos that actually work out the cost of growing things without the sun - https://blogs.cornell.edu/hort/2014/02/15/seminar-video-skyscraper-far… The largest human made solar collectors in the world are agricultural fields and clear glasshouses.

You may consider the Cold War a real world usage for ordinary people: https://blogs.cornell.edu/info2040/2016/09/09/mutually-assured-destruc…

> other fields where such principles aren't really applicable Statistics and reasoning are almost always applicable, and that's the extent science is applied to most fields. If you want people to act in an evidence-based way without invoking trust/faith, they need to understand statistics and be able to evaluate studies on their statistical merit. Unfortunately that's quite difficult and the educational systems we have do a poor job of teaching it. Statistics is subtle. For example, "It turns out, most doctors don’t know actually know probability." https://blogs.cornell.edu/info2040/2014/11/12/doctors-dont-know-bayes-…

All this (SO included) tend to dry up, often because "The Evaporative Cooling Effect in Social Network" hits hard: https://blogs.cornell.edu/info2040/2015/10/14/the-evaporative-cooling-… Islands do survive, and the IRC freenode #postgresql channel is indeed very useful.

Assets that don't increase in value are "losing money", per economic theory. Homes are a low interest money sink. You can buy a home, hold it and get a decent return on your money. You can also mortgage the home at low interest, and gamble that money for higher interest in stocks, etc. You can use rental income to offset your mortgage costs. This is a perfect storm for pushing up costs and denying lower income Americans the ability to pay rent and buy homes. citations: https://blogs.cornell.edu/cradle/2019/02/11/what-the-federal-reserve-g… https://www.forbes.com/sites/advisor/2020/07/28/fed-policy-has-kept-mo…