1827: Survivorship Bias

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Survivorship Bias
They say you can't argue with results, but what kind of defeatist attitude is that? If you stick with it, you can argue with ANYTHING.
Title text: They say you can't argue with results, but what kind of defeatist attitude is that? If you stick with it, you can argue with ANYTHING.

[edit] Explanation

This comic is a parody of entrepreneurial speeches. Entrepreneurial speeches are talks, such as graduation commencements or motivational speeches. The idea behind graduation commencements is that the entrepreneur, having accumulated wisdom and experience in the process of becoming successful, will share his insights and experience to the students, in the hope that they learn lessons that will help them achieve success as well. Companies hire motivational speakers to motivate employees to work hard.

A common theme in these talks is that the entrepreneur succeeded by persisting through hardship, sometimes despite other people telling them they would be better off giving up. They advise students to do the same, and to keep pursuing their dreams even through subsequent failure. While this isn't necessarily bad business advice, this can give students a biased vision of reality, and lead them to imagine that they will succeed as long as they keep trying.

This comic makes a joke about survivorship bias, hence the title. Survivorship bias, or survival bias, is the logical error of concentrating on the people or things that "survived" some process and inadvertently overlooking those that did not because of their lack of visibility. This can lead to false conclusions in several different ways. The survivors may be actual people, as in a medical study, or could be companies or research subjects or applicants for a job, or anything that must make it past some selection process to be considered further. They may also have "survived" on only some of their attempts. For example, although Donald Trump had some successful businesses, he also had many that went bankrupt.

In this comic Hairy is giving a talk encouraging people to "never stop buying lottery tickets". This is an unwise investment plan, because the chances of winning the lottery are mathematically very low and the total payout is usually less than the total ticket sales, meaning the expected return from buying a lottery ticket is (almost) always negative. Survivorship bias applies in this situation since people who eventually win (and, presumably, win more than they've spent on lottery tickets in the time that it took them to win) are much more likely to give inspirational speeches than someone who never won or didn't win enough to make the "investment" worthwhile.

The obvious bad strategy (keep buying lottery tickets) is a metaphor for strategies that successful entrepreneurs recommend (keep persisting and putting money into your start-up); these strategies may be bad on average, but people who pursued them and succeeded are much more likely to be invited and give speeches than people who pursued them and went bankrupt (or people who pursued safer strategies and kept their money), making it appear to students that taking high risks and persisting in the face of expensive failure is the optimal strategy. And those who have done both, such as Trump, are more likely to speak about the successes than the failures and bankruptcies.

Randall says in the caption below the panel that people should be informed about survivorship bias before hearing inspirational talks from successful people.

The title text says "They say you can't argue with results, but what kind of defeatist attitude is that? If you stick with it, you can argue with ANYTHING." In the comic, the speaker's "result" was winning the lottery. Pointing out the survivorship bias is Randall effectively arguing with results, by pointing out that they were obtained randomly, and that it ignores all the other people who may have (foolishly) followed this same process, but never won the lottery. Taken a step further, one could use the survivorship bias to argue against the results of any process, be it research (Any given research process is bound to produce SOME good results, and since those are the only ones published, it is difficult to determine if the research process itself contributed to the good results), business decisions (Some businesses fail, and others succeed, but since only the successful ones stick around, it can be difficult to determine WHY they failed or succeeded), etc..

[edit] Transcript

[Hairy, holding an arm out towards an unseen crowd, is standing on a podium with five large bags around him, each having a dollar sign on it.]
Hairy: Never stop buying lottery tickets, no matter what anyone tells you.
Hairy: I failed again and again, but I never gave up. I took extra jobs and poured the money into tickets.
Hairy: And here I am, proof that if you put in the time, it pays off!
[Caption below the panel:]
Every inspirational speech by someone successful should have to start with a disclaimer about survivorship bias.

[edit] Trivia

  • Lottery with positive return:
    • When item prizes are donated to a lottery (for charity or advertising purposes), sometimes the value of those items may actually be larger than the total price for all of the lottery tickets, if you otherwise would be willing to pay full price for all the prizes.
    • In some lotteries, if the jackpot gets too big -- or goes for too many drawings -- without anyone winning it, the jackpot amount gets "rolled down" and distributed across the lower prize levels. These can have a positive return on average -- but only on the drawings where the jackpot rolls down. People have formed investment groups to buy hundreds of thousands of tickets to exploit these; several such groups repeatedly profited from Massachusetts's Cash WinFall game especially. (The Massachusetts State Lottery has an official report (PDF, 144 KB) on how such high-volume betting affected the game.)
  • Examples of survivorship bias:
    • Diogenes was shown paintings of people who had escaped shipwreck: "Look, you who think the gods have no care of human things, what do you say to so many persons preserved from death by their especial favour?", to which he replied: "Why, I say that their pictures are not here who were cast away, who are by much the greater number."
    • Many people were smoking back in the 1930-70s, thus almost everyone above 80 either smoked cigarettes or was at least subjected to massive passive smoking during those years. Thus anyone above that age could be claimed to prove that you can live a long life while smoking. But they consist of the small group of people that survived in spite of all the smoke, where large sections of those that would have been 80 today, died from cancer or heart disease caused by smoking, long ago, maybe even before they retired. But since these people are dead and gone many years ago, they do not speak up,[citation needed] and are thus the silent majority that is not heard, which is the problem with survivorship bias.
    • During World War II, there was a study of the damage done to aircraft, and the recommendation was to add armor to the areas that showed the most damage. The statistician Abraham Wald noticed that the study didn't take into account aircraft that didn't return: the holes in the returning aircraft thus represented areas where a bomber could take damage and still return home safely. Ironically, Wald himself eventually died in an airplane crash.
    • Anything created by an Earth-human in this universe. We think it's because we're special, rather than being special because we're here/we survived.
  • In the title text, "defeatist" was originally misspelled as "defeatest". This was later corrected.


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Discussion

Is "defeatest" a typo or a joke? I've never seen Randall make a typo before, but I also don't get the joke if there is one. 162.158.2.184 04:28, 21 April 2017 (UTC)

Definitely a typo. Cardboardmech (talk) 04:59, 21 April 2017 (UTC)
At first I thought this was an unfamiliarity with the word, and was about to talk about how it's a real word and what it means, then I noticed the spelling, LOL! I KNOW I've seen such spelling errors several times before - often getting fixed in the next day or two - but I couldn't provide examples even if my life depended on it. And yeah, I'd say this is more "spelling error" than "typo", the I is nowhere near the E on any keyboard. :) - NiceGuy1 108.162.219.88 05:58, 21 April 2017 (UTC)
If itdoesn't get fixed, it might be some weird pun on "[survival of] the fittest". Wouldn't make a lot of sense in the context of the sentence though 162.158.91.233 09:12, 21 April 2017 (UTC)
sometimes Randall do not fix errors, so nothing can be concluded on that (would it be survivorship bias to do so? ;-) How should the word be spelled (I'm not native English speaking), and does the word even exist? The spelling should be mentioned when someone explains the title text. I'm not up for it. And then if it is corrected later, it should go into the trivia section as a corrected error. --Kynde (talk) 10:29, 21 April 2017 (UTC)

It has been corrected to defeatist Rtanenbaum (talk) 13:28, 21 April 2017 (UTC)

Transcript's kind of done. Cardboardmech (talk) 05:17, 21 April 2017 (UTC)

I have changed the format to the usual style and added a bit more detail. But else nicely done. --Kynde (talk) 10:29, 21 April 2017 (UTC)

Other than the title text, does any more work need to be done on the explanation? The Template:Incomplete param is pretty vague right now. ~AgentMuffin

No doubt a lottery isn't a wise investment. However, I have not heard about accepting 25% of the prize or in annual instalments for over a decade before. Is that an american habbit? Vince 141.101.105.174 06:17, 21 April 2017 (UTC)

Never heard of such things, either... Elektrizikekswerk (talk) 08:27, 21 April 2017 (UTC)
This is a thing that some American lotteries do. It reduces the amount that you have to pay in taxes. Mulan15262 (talk) 12:49, 21 April 2017 (UTC)
I don't play the lottery but I have heard of this practice and I think its typical here in the states. As I remember, you have the option of accepting 50% of the prize as an immediate payment or of accepting the full amount in installments over 20 years. With a progressive tax schedule this of course will affect the actual amount received and available for use. The use of payments helps the lottery itself as well and the choices of 50% and 20 years is no accident. The lottery can take the 50% it would have paid directly and invest it. A doubling period of 20 years needs an annual return on investment of only 3.6% (approx) so it works out to be a good deal for both parties. Unless of course your life expectancy is less than 20 years! ExternalMonolog (talk) 00:31, 22 April 2017 (UTC)

The title text is written in the style of an inspirational/motivational speech. Do not be deterred, you can do ANYTHING. Sebastian --172.68.110.58 07:05, 21 April 2017 (UTC)

I took the liberty of editing the very emotional text and replace it with something a bit more "professional", as I think fits this site better. I am still not quite happy about it, as advertising jackpots without taxes and not advertising the payout time are local phenomena only applicable to some jurisdictions, and make no difference to the overall survivor bias that is the theme of the comic 172.68.182.202 08:16, 21 April 2017 (UTC)

I think the whole tax stuff can be deleted. Playing lottery is always stupid - even if there were no taxes on the prize. Elektrizikekswerk (talk) 08:25, 21 April 2017 (UTC)
I agree with Elektrizikekswerk on both issues. Lottery is just tax on low IQ we call it in my family ;-) --Kynde (talk) 10:25, 21 April 2017 (UTC)
I've heard it called "gambling for the math-impaired." Miamiclay (talk) 17:30, 21 April 2017 (UTC)

Third paragraph is taken word-by-word from Wikipedia article on Survivorship Bias. 162.158.92.88 12:54, 21 April 2017 (UTC)

Here's another example of survivorship bias, "We grew up without bicycle helmets and 'nonsense' like that when kids and dogs ran free and we came out fine" but of course I also remember there were a lot of kids with concussions and there were a lot of three-legged dogs running around. Both cases have greatly decreased because of bicycle helmets and leash laws. Rtanenbaum (talk) 13:39, 21 April 2017 (UTC)

And don't forget all the dog bites that came out "just fine"! ExternalMonolog (talk) 00:58, 22 April 2017 (UTC)

If I may suggest, survivor bias is a special example of Bastiat's "That Which Is Seen, and That Which Is Unseen", aka, the Broken Window Fallacy. The logic failure lies in paying attention to only part of the results, not all of them. I'd extend this to argue for acceptance of "The Ends Justify The Means... Buy You Gotta Consider ALL The Ends, Not Just Some Of Them". Saving 100 people is one great end. But if you also kill 10,000 of them, but in the background, where they don't stand out, the ends aren't justified. --108.162.212.227 19:54, 21 April 2017 (UTC)

There actually was a case of a man who won the lottery after buying the same set of numbers every time. Naturally, his advice to everyone was "Keep buying the same numbers every time and you'll win eventually." Of course, there's no way he could be persuaded this was nonsense. Mark314159 (talk) 01:43, 22 April 2017 (UTC)

This is an awfully long explanation, considering that it barely mentions Randall's assertion that *all* motivational speakers should include disclaimers (IE: "Results are not typical."). If compared by net-income versus cost-of-living, the vast majority of people end their lives with less wealth than their parents, in spite of any efforts to better their situation through education, savings, investment, et cetera. In other words, no matter how hard they try, most people lose. That's just a hard economic truth, & many people espousing hard work, dedication & especially sticking to your goals, tend to overlook the fact that financial success is actually quite rare, regardless of the lifelong effort put into it. As stated, nobody hires the failures to give talks; Maybe we should!

Also, speaking to graduating students is far from the most common activity of such professional speakers. The use of motivational speakers at conventions, paid seminars, & sales pitches is much more common & frequent than talks given to students. Since Randall doesn't mention students in any way, I think that specific phrase about students should be removed from the explanation. 141.101.99.11 17:46, 22 April 2017 (UTC)

Less wealth than their parents? While it would be hard to compare, I would argue that they mostly end up better, as technological advances makes economy grow. Although it's true that depressions can reverse it. -- Hkmaly (talk) 00:09, 23 April 2017 (UTC)

This isn't quite relevant to the topic, but please let me vent out about a certain opinion that is going to appear in the explanation eventually: that lotteries are bad investment just because they lose you money on average. This is in fact bullshit, because so does insurance! If you really want to apply math to such things, you need to integrate welfare, not money profit, over the probabilities. Wherein welfare is some half-arbitrary function over money that denotes its actual impact on one's life and that usually grows slower than linearly on positive side (your life changes more after earning the first million dollars than after the second one), but sharply drops on the negative side (a bad debt is a life-ender). With such a welfare($) choice lottery is in fact bad while insurance is good. Note, hovewer, that in some situations, like when you already have a big debt and the mafia is killing you for it next week, lottery makes a surprisingly good, while still unlikely, investment! It's all a matter of the specific situation with welfare($). (Sorry for bad engrish, I never learned all those math terms.) 172.68.182.136 20:18, 22 April 2017 (UTC)

For example, although Donald Trump had many successful businesses, he also had some that went bankrupt.

this is back to front. you need to do more research. --141.101.107.18 12:10, 24 April 2017 (UTC)

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