# Can someone explain the “economics” of StackExchange points?

To date, I had not been bothering to formally accepting my best answer, and had a 0% acceptance rate. On a recent question I posed, I was informed that no one will answer questions with 0%. So, I went back and accepted all my best answers from past threads, and now have 100% acceptance rate. I will also do this going forward.

But what significance do these reputation points have? Bragging rights? Like a video game? What exactly is the incentive structure here, beyond the innate satisfaction of talking about Math with others? Are people using their profile reputation to land jobs, or get paid, or establish credibility in the physical world? This is very cool, and I know most everyone here is a natural learner/teacher, but I just want to know the additional external motivations, if any.

Thank you, and I will surely accept the best answer ;-)

• Accepting an answer indicates (a) you think that the question has been sufficiently answered and (b) you wish to thank that particular answerer by letting the system award him/her with 15 reputation points. The first provides a cue to the readers, the second is being polite. Both are disjoint from the "economics" you asked about. – Willie Wong Jan 8 '13 at 14:32
• You don't have to accept all answers just because someone complains about your accept rate. You certainly should accept them if they solved your problem and you are satisfied with the answer, but you shouldn't accept answers that didn't help you just to increase your accept rate. If you are bothered by an accept rate comment you can just flag it, they are treated special and are deleted after only one flag. – user9733 Jan 8 '13 at 14:36
• Please ignore comments of the sort "noone will answer your questions if you don't pay them". However, please do accept answers if you don't want user to keep going to your question with the intention of answering it, only to find that it has already been exhaustively answered, but not labelled as such. This will free up resources (peoples' time) so they can answer unanswered questions. – Alex B. Jan 8 '13 at 15:13
• I once had a quite similar question: What is the Real Use of Reputation? From there: At 1G reputation, one attains causal interaction with the Platonic universe, including the ability to modify the value of π, the truth value of the axiom of choice and the consistency of large cardinals. – draks ... Jan 8 '13 at 15:27
• Soon the economy will collapse and this reputation will be worth actual goods!!! – Asaf Karagila Jan 8 '13 at 20:13
• "The system asks you to pay for downvoting but upvoting is free. It's a clearly inflationary economy. Endless quantitative easing." -- Ryan Budney – user53153 Jan 8 '13 at 20:25
• This is real economics the day you can buy rep by spending dollars- and the day I'm out. – Michael Greinecker Jan 8 '13 at 22:18
• Rep for sale! Limited time only! Send me ... ahem, $5 by PayPal and I'll give 500 rep bounty to one of your answers. // @MichaelGreinecker – user53153 Jan 9 '13 at 4:44 • @PavelM Did I dig my own MSE grave? – Michael Greinecker Jan 9 '13 at 7:12 • @Michael Taking into account the fact, how much MSE can distract from working ($\approx\$ making money), already the reputation points cost some real money for some of us. – Ilya Jan 9 '13 at 12:52
• Rep points worth actual goods? That could never happen, could it? meta.math.stackexchange.com/questions/4040 – GEdgar Jan 9 '13 at 14:43
• If I'm considering someone for a job and they have an active SO account with good answers, it goes in their favour. If they had an active Math.SE account I would think even more highly of them, though I haven't seen such a candidate yet. – Chris Taylor Jan 9 '13 at 21:31
• Returning to the original subject of acceptance: accepting an answer is the only action by which a user directly increases their rep. (Removing a downvote and deleting a downvoted answer merely recover the points previously lost). This shows how much SE designers wanted the best answers to be clearly marked. // Also, if a hypothetical SE site is started from scratch (everyone has 1 point rep, hence nobody can vote), then acceptances are the only way to start the site's economy. – user53153 Jan 9 '13 at 21:40
• Maybe you could trade points in Second Life? – copper.hat Jan 12 '13 at 18:21
• I recommend focusing on becoming an extraordinary expert instead of wasting time on points. Spend lots of time using deliberate practice to learn lots of challenging, difficult things and later on solve cutting-edge problems. – raindrop Feb 1 '13 at 0:45

## 2 Answers

Economics is a more apt metaphor than other people are giving credit for, but in the end it really isn't "economics."

One thing that I haven't yet seen mentioned is that having reputation enables you to do more things on the site, such as create tags, edit posts, review answers, vote to close/reopen, etc. Enough reputation unlocks moderation tools. Substantial reputations paves the way to moderator candidacy.

Even though reputation isn't a zero-sum system (hint: neither is money), and that giving reputation doesn't cost reputation (except in the case of bounties), in the end the reputation system is something that is held by users and provided to other users.

In other words, I hold the ability to vote (and hence give you 5/10/15 reputation). You want that reputation. Therefore, you have to provide a service that I deem worthy of my vote. Even though my vote costs me nothing, there exists an implicit social contract among many users that quality should be rewarded, and that lack of quality should be reprimanded or ignored. Therefore, the equivalence is that your post meets my standards of quality for giving you a vote.

As with other economic phenomena, we observe patterns that violate this simplistic rule. Higher reputation users tend to earn popularity votes, in the same way that Nike sells sneakers based on brand recognition and not necessarily quality. New users are often given more leeway, and so receive more "charitable" votes even if their post is not the same quality as an experienced user.

All of this also fails to consider the psychological aspects of reputation and badges, which as Qiaochu Yuan somewhat reductively mentions as gamification. In truth, gamification and economics concepts are more intricately related than many think. This is a discussion I could have at length (and one in which I have a fair bit of practical research experience). But the point remains that the system, as originally designed, was created to be an incentivization scheme, but has morphed into an economy of its own. M.SE is probably ideally suited to observe this (SO main is very large, other sites are too small yet).

In the end, the microeconomics are simple: if you enjoy the site, and want to be considered a more substantial contributor, both through intangible reward/recognition, and realizable privilege (enhanced functionality), then you should aim to provide quality commentary, and reward the same in kind.

Economics is not quite the right metaphor. The philosophy behind reputation is gamification. (Economics engages the fancy parts of your brain, but gamification engages the lizard parts.)

For what it's worth, StackOverflow has a careers site, and I understand that employers who recruit using that site do look at StackOverflow accounts. I would not be surprised if similar things started happening with MathOverflow / math.SE within 5 to 10 years (MO participation is already a thing that is being mentioned in graduate school recommendation letters).

• Spot on answer. An irrelevant comment: that economic decisions engage fancy brains rather than lizard brains has long seemed to me like an implicit axiom of economics rather than some kind of (either analytic or empirical) fact. On the contrary, many economic decisions made by real people look pretty lizardy to me. This goes especially for me: I have the skills to make economic decisions in a relatively sophisticated, explicitly quantitative manner, but I have rarely observed myself to do so. – Pete L. Clark Jan 9 '13 at 5:39
• @PeteL.Clark Which part of the brain works in economic decisions is something economics traditionally cares little for. An eloquent statement of this position can be found in The Case for Mindless Economics by Faruk Gul and Wolfgang Pesendorfer. – Michael Greinecker Jan 9 '13 at 7:17
• That's a simplistic description of gamification. – Emily Jan 9 '13 at 19:16
• @Pete: I can relate, but I have to point out that my lizard brain would have long dried my shallow puddle of funds into beer if it could. Luckily I have a primate brain which allows me to have money for food as well. (Although those who met me during the two weeks visit in Vienna, e.g. Michael, may protest the above statement I swear it's true!) – Asaf Karagila Jan 12 '13 at 13:03