>By trading places, students could get another shot at a place. At schools for which they already had a go in the lottery. This would give them better chances. At the expense of students that don’t (or can’t) trade. This is unfair.
This is culturally alien to me; the students receiving the benefit are not harming other students.
>Another argument, that is related, is about strategizing. Students were told (correctly) that their best strategy was to give their true preferences. If trading were allowed, this would not be true. It would pay off for students to put popular schools high on their list. A spot at these schools would be good trading material.
Solution: only allow trades that are in accord with the students' submitted preferences. That is, if Alice prefers Central to Devonshire, and Bob prefers Devonshire to Central, then we could allow Alice and Bob to switch if their submitted rankings indicated that these moves were consistent with their desires. There would be no incentive to lie.
> This is culturally alien to me; the students receiving the benefit are not harming other students.
It's not just "culturally alien"; it's a straight-up error.
> Solution: only allow trades that are in accord with the students' submitted preferences. That is, if Alice prefers Central to Devonshire, and Bob prefers Devonshire to Central, then we could allow Alice and Bob to switch if their submitted rankings indicated that these moves were consistent with their desires. There would be no incentive to lie.
Wait, why is that a 'straight-up error'? They explained why it would harm other students - because it would incentivize students to choose popular schools instead of schools they actually wanted, in hopes of gaining a good trade opportunity. They don't want strategy to come into play, because some people are better at strategy than others.
It isn't an 'error', it is just a decision that they don't want strategy to be a factor.
Yes, the incentives this sets up could be bad for subsequent rounds; that is absolutely a real problem. But this passage seemed to be suggesting that trading, in and of itself, harmed students who were not involved in the trade, and that's not correct.
Something being unfair is not the same as something harming someone else. Lets say I have a cookie, and there are 10 kids in front of me who like cookies. If I give any kid a cookie for any reason, it doesn't HARM the kids who don't get a cookie; they are no better or worse off than if the cookie never existed. However, suppose I decide to give the cookie to the tallest kid - even though none of the other kids are harmed, this is still not a 'fair' situation.
You can do no harm and still be unfair. Whether that is bad or not is subjective, but it is still unfair (in the sense that every kid has an equal chance at the cookie).
Actually it does harm the ones who don't get it. Beyond basic necessities of life, everything else we get is pretty much only good because it's better than what someone else gets. That's the essence of why discrimination is worse that just everybody being poor, and why high wealth inequality is bad even though most people have as much money as they need. It's emotional, not purely practical.
Absolutely yes. Educating and informing increases suffering. Anyone involved in making information more accessible and the world more connected is enriching themselves at the expense of humanity as a whole.
This is quite literally why we can't have nice things.
Fairness in this context (and often) is a highbrow word for unacknowledged, uncontrolled jealousy.
Sorry, I just realized that I failed to point out which part I was saying was "a straight-up error"; it's kind of buried in the sentence. My mistake! With emphasis this time:
>By trading places, students could get another shot at a place. At schools for which they already had a go in the lottery. This would give them better chances. At the expense of students that don’t (or can’t) trade. This is unfair.
The emphasized part is what I'm objecting to. Sorry about that.
Let's say there is a lotto for concert tickets. If I pay 1,000 people to take part in that lotto who don't want the tickets then I get an 'unfair' advantage.
The logic is similar for the school lotto as people would target schools based on their ability to trade not necessarily their actual preference. This would lower the odds of people who otherwise had fewer options.
AKA, if only bob or sam want a spot sam's odds are 50/50%. But, of ted joins but would always give his spot to bob then sam's odds are 1/3 and bob's odds are 2/3.
Ok, I think we are having the exact same discussion in two threads. I will stop responding to this thread since I answered your objection in the other one :D
>> Solution: only allow trades that are in accord with the students' submitted preferences. That is, if Alice prefers Central to Devonshire, and Bob prefers Devonshire to Central, then we could allow Alice and Bob to switch if their submitted rankings indicated that these moves were consistent with their desires. There would be no incentive to lie.
>It's not obvious to me that this is true?
Even if you could solve the game theory issues, you wouldn't solve the problem of people selling spots in desirable schools.
Suppose two students have identical rankings and end up with the same school. If one of them manages to trade (e.g. because they quickly manage to find someone that wants to trade with them), they have an advantage over the other student who is stuck with their lottery result. This is the unfairness the article talks about (besides the strategizing argument).
Perhaps this can be remedied by automatic trading and another lottery, determining the order in which people get to trade, but that still doesn't solve the problem with strategic choices.
> > This is culturally alien to me; the students receiving the benefit are not harming other students.
> It's not just "culturally alien"; it's a straight-up error.
Perhaps an exaggerated example will illustrate. Students are assigned by a lottery system that sometimes allows pairs (or triplets, etc) of students to have a beneficial trade. Then students are permitted to use dutch-school-trading.com to swap schools. Except that students who own computers are permitted to engage in this extra round of trading while students who do not own computers are not. Some consider this to be biased against students who don't own a computer.
In reality, it's not the single factor of "owns a computer" which is at play, but multiple issues including social connectedness, strategic thinking, free time on the day the placements are published, and so forth.
This would be a stable matching (after allowing these changes). Since Nash is guaranteed here, there would be no reason to lie on the original form, unless there's some weird mixed equilibrium (that's not pure). It'd be interesting to see what conditions we must have on it (if it even exists! I'm not sure to be honest), but the only pure equilibrium is certainly a stable matching.
I'm curious if you could make trades automatic if all students involved benefited as per their preferences in such a way that it would be impossible to game.
I think though that it would still be possible to game for any variant I can think up.
Only in the short run it isn't. On the long run, school trading creates incentives which make the entire system worse.
So you're not just optimizing for a single round of students, you're optimizing for the future rounds of students. And pareto-optimal makes no sense when you're looking at future rounds with different students.
But you could create a pareto-optimal analogy: allowing two students now to trade place in a seemingly pareto-optimal way would actually harm other students when you look at the future rounds, so the trade actually isn't pareto-optimal.
It isn't Pareto-optimal in the long run either. Pareto-optimal doesn't mean "optimal" or perfect. It just means there is a way to increase the satisfaction of someone without decreasing the satisfaction of someone else.
It's not even designed to deal with repeat situation, incentives and strategizing. It just looks at the outcome and says: is this optimal?
> It's not even designed to deal with repeat situation, incentives and strategizing. It just looks at the outcome and says: is this optimal?
That's exactly what I'm saying:
> And pareto-optimal makes no sense when you're looking at future rounds with different students.
And that's why I talked about a time-series analogy of pareto-optimality:
> But you could create a pareto-optimal analogy: allowing two students now to trade place in a seemingly pareto-optimal way would actually harm other students when you look at the future rounds, so the trade actually isn't pareto-optimal.
In that sense, you don't just look at the students selecting now, but at the future students as well. In that case, allowing trades now leads to dissatisfaction in the future, so while allowing trades now might seem to lead to a pareto-optimal scenario, it doesn't lead to a time-series-pareto-optimal scenario.
I think he's saying that the error is in the original assignment algorithm: it produces a solution that is not Parto-optimal. If it was, there would be no mutually advantageous trades. One way it could achieve that is by randomly doing mutually improving trades until none are left.
But you can't consider just the current round of students when designing such a system, you need to consider all subsequent rounds.
In that case, allowing trades now leads to dissatisfaction in the future. So, while allowing trades now might seem to lead to a pareto-optimal scenario, it doesn't lead to a time-series-pareto-optimal scenario.
The alternate system I described doesn't involve "allowing trades" and therefore can't create perverse incentives or affect subsequent rounds.
The idea is to make an algorithm that performs a Pareto-optimal assignment algorithmically, so that no possible mutually advantageous trades exist when it is done. It's totally possible for an algorithm to do that, and the current Dutch one clearly doesn't.
One possible way is to run the current algorithm, and then as long as the solution is not Pareto-optimal, perform a swap at random from the set of all pairs of students where swapping would improve both of their preferences. This can be proven to converge with sufficient steps. Doing this kind of swap algorithmically has nothing to do with "allowing trades". I'm calling them "swaps" instead of "trades" here to make clear there is no manual action involved on the part of the students.
I hope this clarifies what I meant, and why objecting to "allowing trades" does not make sense as a response.
> Solution: only allow trades that are in accord with the students' submitted preferences. That is, if Alice prefers Central to Devonshire, and Bob prefers Devonshire to Central, then we could allow Alice and Bob to switch if their submitted rankings indicated that these moves were consistent with their desires. There would be no incentive to lie.
This is just false. You're still incentivized to place popular schools farther up than you otherwise would.
Say you decide to list Populonopolous higher than Nirvana, even though you would ultimately like Nirvana better. There isn't space at Heaventy, so you are initially assigned to Populonopolous. This won't help you get into Nirvana, because you can't trade downward on your preference list. But as long as someone else got assigned to Heaventy that would have preferred Populonopolous, you could trade with them.
This is exactly how it's supposed to work according to the academic whose work it is supposedly based on (Roth et al).[1] I don't know why Amsterdam didn't include automatic, mutually-advantageous trading in the algorithm.
> This is culturally alien to me; the students receiving the benefit are not harming other students.
I don't think that this is culture. I believe that this is just math. If we devise some system that solves some optimization problem, we shouldn't meddle with that system by other means, like "common sense". We can use common sense to find possible improvements to the system, but we shouldn't apply this improvements without checking them with science laying behind system. Unchecked common sense can break system's promises entirely.
> Solution: only allow trades that are in accord with the students' submitted preferences. That is, if Alice prefers Central to Devonshire, and Bob prefers Devonshire to Central, then we could allow Alice and Bob to switch if their submitted rankings indicated that these moves were consistent with their desires. There would be no incentive to lie.
How could we know their desires? If Alice and Bob start to think creatively about it and find a way to lie about desires? Maybe they find some tradeoffs, like less chance to get into their top school against more chance to be able to trade then?
The more complex system is, the more loopholes in it, the more complex and obscure strategies becomes available.
Imagine school A is popular with rich kids, now I prefer not to go to A because some reasons, but I could put A on my list and if I get A then I could trade with a rich kid(and ask for some extra without authorities to know)
> This is culturally alien to me; the students receiving the benefit are not harming other students.
I think there was some similar reasoning in a Florida school vouchers case. (Which might've more recently been overturned?) Opponents of the vouchers program argued that the Florida constitution required education to be "uniform":
Now instead of drawing funds directly from the district, you're subsidizing private schools at the state level.
I send my son to catholic school for various reasons. It's my choice and my cost, and the school provides scholarships to help those less able.
In my state, only a few things common to all students are provided/funded by the state in private schools: non-religious textbooks, school nurses, some transportation and limited bussing to special education.
Personally, I'm comfortable with that model. I am uncomfortable with the state supporting any church, including my own.
> Now instead of drawing funds directly from the district, you're subsidizing private schools at the state level.
In California for instance, 57% of school funding comes directly from the state, so that's no change in funding source.
Personally, I don't see a difference between funding a religious school and a secular private school, both are capable of following a particular philosophical bent and applying it liberally or dogmatically.
To be honest, I think the idea that we can fund any philosophy except one that touches on cosmology (i.e. religion) is an unnatural discrimination against religion.
> if Alice prefers Central to Devonshire, and Bob prefers Devonshire to Central, then we could allow Alice and Bob to switch... There would be no incentive to lie.
To be fair, there is an incentive to lie when you add neighborhood and other preferences to the system. Say Sally, who wants Central, lives near Devonshire and thus is given better odds of getting a spot there. If Dick wants Devonshire but doesn't really care about Central, it gives him incentive to lie and rank Central higher to increase his chances of swapping with Alice.
Far from an exotic scenario, this is exactly what happens in the SFUSD system.
Win-win swaps could be done automatically by the lottery system. This eliminates the non-fairness objection (as this optional upgrade can happen to anyone). It does theoretically create room for strategizing though: If there is a very popular school that I don't want to go to, it makes sense to put in down as option #3 or #4 because if I get it, I might slingshot back into my #1-#3 options.
> It does theoretically create room for strategizing though
And that is the exact issue with it: it would soon be common knowledge that you should do so, and then the people who don't consciously try to game the system would be at a disadvantage.
In general that seems to be the goal: devising a system that cannot be gamed in any other way than giving your honest preference. In other words, ensure that the system is a self-enforcing protocol.
...and that would reduce efficiency again. It's not at all clear that the loss of efficiency from false preferences is smaller than the loss caused by students getting each others preferences.
In fact, the article is a little too kind to the option of trading places. It presents a clean choice between fairness and efficiency: trading harms the former while boosting the latter. In fact, trading will reduce future efficiency due to strategizing; it may well be that trading is a straight-up de-optimization in all but the current round.
San Francisco United School District uses the multi-DA system, but here's the kicker: it bakes exchanging into the algorithm.[1] They call it "trading up"; most parents here refer to it as "swapping".
It works more or less as described, where you list off all the schools you want in order of preference. It runs lotteries for each of them in parallel and you get the highest listed one you win. But then it does one more thing: If it finds mutually advantageous swaps, it does so automatically and instantly. In other words, it's not up to or necessary for the student to do it manually.
In fact this feature is detailed by the Ivy League team that put it together, including Alvin Roth, as early as 2010.[2] So while this article is well written it seems to give a less than complete picture. Why did Amsterdam not adopt this feature?
P.S. There is much to be said about the SF lottery system which is a fun / highly stressful topic for nerds and parents. If you like these kinds of problems I encourage you to take a look. It also tries to solve for giving preferences to neighborhood schools and disadvantaged families, while also offering special language and K-8 programs that serve the whole city fairly. The goal is to eliminate strategizing as much as possible, but it's very interesting to see people figure out some hacks.
I disagree about the "fun" part having just gone through this with my first kid. I agree with the Dutch, swapping (at any point in time) adds an edge of unfairness to the process:
- In a situation where all decent schools are oversubscribed swapping 100% encourages (and rewards) setting up your school list strategically. Which helps out families that have the time to collect the information needed and sort their schools appropriately (we spent a bunch of time researching / planning here, but knew off other families who _really_ got into gaming the system)
- In one of the meetings where the slide you linked in [1] was displayed, they offhand mentioned that the swapping order is done alphabetically. When asked if kids with A* names will get better swaps they kinda ignored the question and moved on. But how are multiple tied swaps resolved?
- Also, from what we were told, the swapping doesn't respect the "lottery weight" that locals, poor test score neighborhood kids, or siblings get. If that's important, shouldn't it apply to all phases of the process? (I'm aware the math here might get out of hand)
I started out thinking that the swapping was a good idea, but when I saw how much it encouraged and rewarded strategy in building the list of schools I changed my mind. It's not a fair process. It's a system that rewards families that have likely already been rewarded by society.
This incentivises people to put popular schools which they don't like lower on their list (3-5), so that if they miss their top school, they can get into a popular school and swap with people who are at their desired school. Which removes the property that honesty in school rankings is the best policy.
Yeah, but what if they do like the popular school as a backup? Wouldn't eliminating swaps lower the average rank of assigned schools, and thus decrease happiness?
Lower average rank of assigned schools might mean decreased happiness, but this system also increases fairness because those who game the system tend to be better educated/more privileged. Disallowing swaps forces people to rank schools honestly and prohibits such gaming of a system.
I haven't heard flattering things about SF school system--mostly directed at the lottery. I remember hearing that half of kids born in SF move away before entering school, another half go to private school. I can't find the source, but I had read this article when it was published[1]. It says 30% of students go to private schools.
That's not necessarily due to the lottery alone. That will happen when the schools are underfunded and less desirable than private, regardless of how equitably assignments are distributed.
A majority of students get their first choice public school.[1] However there is a lot of competition for a handful of the most desired schools. Only a small percentage of students request their local school first, but if you live near a popular school and you don't get it, it is frustrating. You may end up getting placed at a much less desirable school farther away. People blame the lottery for that, but ultimately the "best" schools don't have enough seats.
This sounds a lot like the Single Transferable Vote system that some of us are pushing for in Canada. Same principle, you rank all of the parties that are acceptable to you, and your vote is applied to the first candidate who isn't eliminated.
This way, if I want the Green party, and am willing to settle for Liberals, but can't stand the thought of a Conservative win, then I can support my favorite party without risking a split vote that lets the hated party squeak in with ~38% of the vote. Naturally, those of us who vote for fringe parties are strongly in favor of STV, and those who benefit from split votes complain that it is too complex for the average voter to understand.
You might find Mixed Member Proportional an interesting option. It is directly proportional in the party vote and also includes electorate MPs. It does not suffer from some of the strategic voting problems that STV suffers from.
> To allow trading would be to enable strategic behavior in future years...it could also give an unfair advantage to students that are better at strategizing — and to students that have more resources to make good strategic decisions.
Similarly, it could enable wealthy students to buy slots from poorer kids. Poorer kids could choose to prioritize schools that are popular, but that they don't actually want to go to, in the hopes of trading places with a rich kid who was willing to pay for the privilege.
Amsterdam is a very special place. You know how on HN everybody always complains about insane all kinds of legislation in SF? Well in that respect, Amsterdam is the SF of the Netherlands. So please let this taint your opinion of Amsterdam, and not of Europe or the Netherlands.
They really like rules and regulations there. More is better. Notably, the whole concept of a high school lottery is culturally alien to most of the country. Let alone a lottery with a 1000-page rule book and court cases.
Why taint? The judge gave good reasons for disallowing trading. In particular; if students know they can trade places later, they'll pile onto the most popular schools (rather than their true preference) knowing that if successful they can easily trade their place for another one (including their preferred school which may not have selected them). Add to this the possibility of paid trades, I think it's great they're keeping it fair and simple.
Yes, Amsterdam loves regulations. But Amsterdam is quite uniquely positioned in NL. The popularity of the city with locals as well as tourists is of an entirely different level than the rest of NL.
Furthermore, the AMS lottery systems is precisely a regulation that is far from pointless. This article explains it very well.
Fascinating. As an outsider this reads like a wonderful attempt by those with difficult decisions to make to be as fair as possible to all of the young people for whom they are responsible.
The only thing this has done is raise my estimations of the public servants in Amsterdam.
Living in another part of the Netherlands, I haven't seen a significant difference. The Dutch have an altogether practical outlook, valuing regulatory conformity. One cannot even choose to paint the exterior of their house differently.
The main difference with Amsterdam is primarily the size of the city: greater size makes for more schools and greater variability between them. Greater variability creates a differential in desirability, thus creating the problem of allocation... to which they have devised a very Dutch solution.
If they allowed trading, then there's nothing to stop the lucky winners of spots at popular schools from selling their spots, or for losers of spots to offer bounties for their top choice. As an argument for, "Win-win swaps" comes up a little thin when you consider the sort of economic shenanigans that folks can engage in.
If they allowed trading, then there's nothing to stop the lucky winners of spots at popular schools from selling their spots, or for losers of spots to offer bounties for their top choice
Who cares? If people prefer cash to a spot at a particular school, let them have it.
We care, and you should care too: the effect of that policy would be the exact opposite of fairness, the rich would go to the best schools while the poor would get a handful of cash and the worst education.
There are nation wide tests at the end of primary school (to get into high school) i.e. CITO and NIO I believe. If you score well on these tests you get a good 'advice' which is non-binding which this post is about.
I had a near perfect CITO score but a literally retarded NIO score because they explained me how the test worked wrong (I was probably being stupid and WAY took their words LITERALLY [1]). So they basically averaged my scores (best and worst) and said "Well you go to the HAVO" which is average.
My parents did NOT sit well with that and just said "No he's going to Gymniasum (highest possible class with Latin/Greek) whether you want it or not. We all know he just screwed up there on that one tests because you explained him the instructions wrong."
Anyway, 11 years later and I'm doing a PhD in applied mathematics. I'm really happy my parents fought for me to go to Gymnasium and I'm so glad the advice isn't binding. I'm not sure whether it still isn't binding or they changed it somehow.
[1] The instructor told us that "at the end of your test you will have time to finish your questions". So what stupid little me did was I made half the test, then I waited till the time ran out and when they took my paper I asked "can I finish the questions now?" And they just took my paper away.
I wanted to give you a brief explanation, but I ended up summarising the entire
Dutch school system. I also just found out there's a comprehensive-looking
Wikipedia article [10] on the matter, so perhaps this wall of text is
unnecessary. I have added sources, primarily on Wikipedia, some in Dutch and
some in English. I only used them to check some facts.
How the Dutch school system works:
The school system in the Netherlands is separated into three stages: primary
school, secondary school, and higher education.
Primary school is separated into 8 stages, which normally correspond to years.
These are "group 1" to "group 8". Children start school roughly when they are 4
years old, but education is compulsory from age 5. These 8 years increasingly
introduce different subjects and increase difficulty, with reading, spelling,
and arithmetic in group 3, English starting in group 7, etc [1].
During primary school, progress of each student is tracked using tests,
allowing the teacher to see how the child develops. Near the end of primary
school, the teacher gives a formal "school advice" for the secondary school
level. There's also a final test after this, and if the student excels
unexpectedly the school needs to reconsider their advice and possibly adjust
it. This test is an extra piece of data for the secondary school to consider.
The primary school's advice determines which level of secondary schooling the
student can enter [2]. The secondary school may not base their acceptance on
other tests and may not require any extra tests, unless they provide a
"special" kind of education, like bilingual education or education focused at
professional sports. In that case, the extra test may only test the student's
special abilities required for the school.
Secondary school [3] generally takes between 4 and 6 years, and is divided into
four levels of increasing difficulty: practical education, vmbo (+ mbo),
havo, and vwo. Practical education [4] does not have a specified duration
and is meant for students with particularly low intelligence (60 to 75-80) and
a learning delay of at least 3 years. Vmbo [5] is preparational secondary
vocational education and is again divided into 4 levels, in increasing order
of theory-orientedness. It takes 4 years and ends with a final, nationwide
exam. It prepares the student for a job, for havo or for mbo. About 60% of
all students in secondary education follow vmbo.
After vmbo the student can go to mbo [6], which is secondary vocational
education. It is focused at joining the job market and, again, divided into 4
levels. The first level does not actually require any previous qualifications
and educates the student to become an assistant professional, the second
level prepares the student to become a basic professional, the third level
prepares the student to become an independent professional, and the fourth
level prepares the student to become a specialized professional. The fourth
level also allows the student to progress to hbo. Mbo corresponds roughly to
community college in the US.
Havo [7] is higher general secondary education, takes 5 years, and is
followed by about 20% of all secondary education students. Havo prepares the
student for hbo, but after 3 years one can also be admitted to mbo. Vwo [8]
is preparational scientific education, takes 6 years, and is also followed by
about 20% of all secondary education students. It comes in a few variants,
primarily atheneum and gymnasium. The difference between those is that
gymnasium includes Latin and/or Greek. Vwo prepares the student for wo.
Higher education consists of hbo [9], higher vocational education, and
wo, scientific education. Hbo is focused at the application of scientific
knowledge, while wo is focused at scientific research. These follow the
international standards for higher education.
As an aside, the terminology around higher education can be a bit confusing
when translating between Dutch and English. Hbo is delivered at a "hoge
school", which translates literally to English as "high school". The proper
English term is "university of applied sciences". Furthermore, in Dutch wo is
commonly (even usually) called "universiteit", Dutch for "university". When
doing hbo, saying in English that you are a university student may therefore
feel like a lie, while being correct.
You can always rely upon economists to exclude any human considerations from the process.
There is no choice here because it fails the 80/20 rule of any hiring system. Any less than 20% capacity spare and there is no free choice.
So since there is no actual choice, why give people one? Is it the same as with toddlers - You can have red juice or blue juice - a way of giving the feeling of control without actually having any.
Giving people a choice and then not giving them what they want causes loss aversion responses. That is worse than not having any choice at all.
Kids want to go to the nearest school and the schools should be sufficiently equipped to cater for all needs in the area.
Every other solution I've seen is more difficult than that one and is based around psychological manipulation rather than solving the problem.
And no the 'free market' won't provide. You're supply side limited by the number of people capable and willing to be teachers. That's why you have to have a mass production system for education.
Why can't capacity expand to adjust for demand? Sure, not always possible, but in many cases it could be.
Kids want to go to the nearest school and the schools should be sufficiently equipped to cater for all needs in the area.
Nearest school to what? I used to go to a school quite far from my home, but within walking distance from my grandparents home, who took care of me for a couple of hours after school. I had friends who went there because it was close to the swimming pool where they trained.
We had that option because it was a non-profit school ran by a socialist cooperative, instead of the local rigid public system (talk about ignoring human considerations!).
Everybody does live near a highschool, but that way you end with bad and good schools because of economic indifferences.
They are doing this (rather than just basing it on location alone) to spread the pain and more importantly give children born into this world the same chances irregardless of the social economic situation of their parents.
Locality still plays an important role, but we are talking high population density neighbourhood. Most will live near at least three schools in an radius of 30m walk (10min bike ride)
Oh yes. I was arguing the (from the eyes of the government) optimal allocation isn't perse the same as maximizing the preferences of the individuals. Which is similar to your argument, except i'm emphasizing its intentional -- not a mistake. From their perspective they can help students that are not as well off, but not if they are concentrated in a single school.
I wasn't giving an opinion on whether any of this was a good (as in moral) idea or not. Although i understand there is an argument to prevent schools from becoming a political, cultural and racial mono-culture, even if a majority of the students would prefer to be at a school with 'just their kind of people'.
French universities have adopted a similar system. For some reason they do not like to select students based on merit, and there are more candidates than seats, so they introduced a lottery to determine who gets to go to university. It's very curious from the outside and even being French I can't think of a good reason for this system. Basically telling students it doesn't matter how hard you work in high school, it has no impact on whether you will work in a bank or a factory...
Are French high schools reasonably homogeneous in their quality? Otherwise a merit-based system would be massively discriminating against students which made a poor choice (or live in an area without much of a choice).
Not really. State controlled schools in theory are supposed to take students based on postcode only, but in practice the most prestigious do their own selection. And you also have lots of private schools that are even more heterogeneous.
The French system is very paradoxical. By trying to be very egalitarian it is achieving the opposite result.
For high schools, the postcode allocation makes that wealthy areas where parent tend to be all highly educated have much better schools, whereas the poorest suburbs where immigrants live when they first arrive in France, have become educational toxic waste lands. And since teachers do not want to live there or face these students, they also get bottom of the basket teachers and high turnover.
The mainstream universities, because of a long standing practice of having no selection, are chronically over-crowded and under-funded and their reputation has gone down the drain, outside of a few disciplines, like medicine, where incompetence has too great consequences, and which maintained a good reputation based on competitive exam selections.
In parallel to universities, you have grandes ecoles which are small universities (student count wise) but very selective and very prestigious, and from where the vast majority of company executives come from. In theory these grandes ecoles are very egalitarian too, the entrance is based on a very selective competitive exam in math, physics, economy, etc and are either free or cheap (outside of business schools). To prepare for this exam, students go through a 2/3 years preparatory school, with a very intensive and demanding curriculum. Most students keep a horrible memory of these years and these preparatory schools are known for being a "not for every student" experience. As a result, teachers in poorer areas (who did not go through these schools themselves) discourage good students from enrolling ("it's not for you, too hard"), whereas parents who themselves went through this system apply pressure on their kids to do it anyway. As a result, you end up with a massive endogamy.
I'm the parent of a kid who took part in the 2015 school lottery in Amsterdam, and since I had skin in the game I went as far as studying the original nobel prize winning papers on the DA algorithms to understand exactly what was going. This article is actually a really good summary, the amount of misinformation out there being spread by journalists who did not fully grok the (admittedly complex) system is astonishing.
One thing that the article only touches on is the "preferred placement" that some schools managed to bring in from the old system, e.g. Montessori kids get preference for Montessori schools. This ruins the elegance and inherent fairness of the algorithm. In particular it makes it possible to do some form of strategic selection again if you have a preferred placement option that you can trade. This tends to benefit kids with clever parents disproportionately, as the article notes.
A "lesson learned" for policy makers should be that even though an algorithm performs better on being "fair" (Multi-DA), it can still be better to choose an algorithm that is easier to explain. (They did end up switching to a different algorithm the next year)
Obviously it's not failing, but it could be succeeding despite this. Especially since has it's been pointed out, most of the Dutch educational system does not use this mechanism.
I thought the argument was going to be that exchanges would lead to poor students applying for top schools only to "sell" their spot to the highest bidder in a swap.
It would seem though that some exchanges could take place within the lottery system itself. If two students were accepted to their second choices, and swapping them would give both their first choices, then that should be an optimization pass run after the lottery pass is done.
My main concern would be that there is no way to control the potential hidden transactions included in the trades. I can well imagine less well of parents or parents less concerned with education gambling on the most desirable schools with the sole intention of making a buck on the trading aftermarket, or overly keen parents with less inhibition putting severe pressure on other parents to force a trade.
This seems like an extreme example of "good in theory" overriding "good in practice".
The multi algorithm outperforms single, so run multi, then greedily swap students at random until there are none that got each other's higher ranked choice.
This obviously outperforms multi, and is fair, strategy-resistance be damned.
They could only allow trading if you didn't get into your top 3 schools. That way you couldn't really count on being able to trade and only the people who were really unlucky could trade.
Closer to what, though? If, for example, you practice some kind of after-school activity not near to your home, you might be better off choosing a school near it, and the footprint is the same.
It's better to discourage the harmful activity directly than to impose indirect restrictions, since those discriminate against specific groups.
> Suppose, for example, that a student’s top choice school is hugely popular. But their number two to five schools are only slightly short on places. Then it could make sense to register for the number two school in the first round. They would have good chances to get into the second best school. Going for the number one choice is risky: if they don’t get in, they have no shot at any school in their top five anymore.
Why would not getting into the first-choice school affect the student's chance of getting into any of their top five schools? The article's earlier description of the Boston method makes it sound as though this wouldn't be the case.
I'm going to repost the same comment I made on /r/math:
> By trading places, students could get another shot at a place. At schools for which they already had a go in the lottery. This would give them better chances. At the expense of students that don’t (or can’t) trade. This is unfair.
This argument here is not correct. It's not at anyone's expense. The two people trading both benefit, and other students are unaffected. Not everything is zero-sum; not every benefit is at somebody's expense! (The strategy argument -- that people had been explicitly told the system was strategy-free, and it would be wrong to go back on that guarantee by allowing trading -- makes much more sense.)
This is an interesting article about social choice theory but the non-mathematical parts seem to be making some implicit assumptions about "fairness" that are, let's say, not exactly uncontroversial. And the argument I point out above is just in error.
You are missing some key points - if they allow trading, they are going to incentivize people choosing popular schools instead of ones they actually want to go to. Since more people are going to choose popular schools in hopes of getting a good trading asset, people who ACTUALLY want to go to those popular schools are going to be less likely to get in.
Your assertion that it is an 'error' is only true if they only allow the trading to happen this year (after the preferences were set), and not in future years. The trades are only pareto-superiour if there are no future decisions to be made; since this is a repeated game, allowing pareto-superior trades this year means that next years game will NOT be fair (by their definition of fairness).
I agree that their definition of 'fairness' is not objective, but it is one they have decided to go with; they decided that the ability to strategize is not evenly distributed, and so allowing strategy is unfair.
Note that even if everyone were equally able to strategize, doing so would reduce efficiency: after all, to strategize students lie about their preferences, and the lottery takes those lies into account. It's the garbage in; garbage out principle. Some of the stratgizing students will get into schools on their list they really only put there as a trading option.
So it's not just about fairness; it's also about ensuring the algorithm works in the first place.
Yes, the incentives this sets up could be bad for subsequent rounds; that is absolutely a real problem, as I mentioned. But this passage seemed to be suggesting that trading, in and of itself, harmed students who were not involved in the trade, and that's not correct.
Notice it explicitly says:
> This would give them better chances. At the expense of students that don’t (or can’t) trade.
But in fact those students are unaffected.
In subsequent years, as you say, it is a problem. But I don't see how to read that part as anything other than denying that when just restricted to that year it is a Pareto-improvement.
You may say "well that's a self-evidently stupid claim; of course they're not making that claim, because that would be stupid". But there's a lot of people out there who really seem to believe in a zero-sum world, and are convinced that when anyone's position improves, that means that everyone else has been harmed. That Pareto improvements are fundamentally impossible. There are absolutely people out there who would make that claim.
This IS a zero sum game, though. There are only x number of spots at each school.
I agree that the wording of 'at the expense of' is a bit misleading, but I don't think it is categorically incorrect. The idea of fairness can, by certain definitions, even encompass pareto-superiour situation, if the improvements are not distributed fairly.
I gave this example in another comment:
Lets say I have a cookie, and there are 10 kids in front of me who like cookies. If I give any kid a cookie for any reason, it doesn't HARM the kids who don't get a cookie; they are no better or worse off than if the cookie never existed. However, suppose I decide to give the cookie to the tallest kid - even though none of the other kids are harmed, this is still not a 'fair' situation.
You can do no harm and still be unfair. Whether that is bad or not is subjective, but it is still unfair (in the sense that every kid has an equal chance at the cookie).
Of course, whether being absolutely fair is worth foregoing pareto-superiour improvements is a moral argument, and there is no objectivly correct answer to that.
I'm afraid the beginning of your comment contradicts your earlier statements. Earlier you agreed that in that restricted situation, it is in fact a Pareto improvement. However, now you are saying it is a zero-sum game. There are no Pareto improvements in a zero-sum game!
The rest of your comment just returns to the claim that the whole thing is unfair even though nobody is harmed. But that's not the part I'm claiming is wrong! The part I'm pointing out as a "straight-up error" is the part where it denies that (in the restricted context of a single year where people didn't know that trading would be possible) is indeed a Pareto-improvement. I'm not making any argument as to the broader fairness.
Not sure I understand. If I want to go to the 10th best place why would I attempt to get #1 in the hopes of trading for #10. My odds are better if I apply to #10
But other students are affected, namely next year's (and later) students, and especially those who are not so good at strategy. You must consider them too to evaluate the fairness of the rule.
And missing from all the analysis I've seen so far: some nations have baked "equality" into their approach to legal decisions. The trading policy was deemed discriminatory, enhancing some students at the "expense" of others.
"At the expense of" means "so as to cause harm to or neglect of".
The other students were not directly denied something, and did not lose their spots in school. What they would have lost, had the swapping been permitted, is an equal and fair treatment by their government and laws while being placed in school.
As swapping allows some "haves", thereby also creating "have nots", the government deemed that to be enhancing some "at the expense of" others who were denied equal opportunity and treatment under the law. They lost fairness, equality, and "freedom" (in American parlance).
I mean... "Whites only bathrooms come at the expense of civil liberties." is not a controversial assertion.
The judge ruled that everyone not being equal causes harm/neglect. ESL author Ronald de Haan was using the word and phrase correctly, I think it is being misapplied in most of this discussion by a degree of pedantic over-parsing.
I would say you are arguing against quite a contrived point. The article speaks about the methodologies for holding fair lotteries in the context of doing this year after year. You are technically correct that allowing trading once wouldn't harm other students, but that is quite beside the point. The judge made this decision primarily on the basis that subsequent lotteries have to be held.
> You are technically correct that allowing trading once wouldn't harm other students, but that is quite beside the point. The judge made this decision primarily on the basis that subsequent lotteries have to be held.
I gotta disagree:
Harm in this case is not the distinct action of losing a spot in school.
Harm, as ruled by a judge in accordance with their legal system, is the unequal handling and unequal distribution of opportunity to a legally mandated, tax-funded, government service.
The judge ruled the swapping unfair as it is _discriminatory_. The ESL author used a (highly appropriate!), term that's being parsed to death here based on a north american civil perspective.
Had we seen this ruling in the states we would say the swapping was "unconstitutional under the equal protections clause". Because making some people more equal some of the time makes the rest of us less equal all of the time. The winners are enhanced at our collective expense.
This is culturally alien to me; the students receiving the benefit are not harming other students.
>Another argument, that is related, is about strategizing. Students were told (correctly) that their best strategy was to give their true preferences. If trading were allowed, this would not be true. It would pay off for students to put popular schools high on their list. A spot at these schools would be good trading material.
Solution: only allow trades that are in accord with the students' submitted preferences. That is, if Alice prefers Central to Devonshire, and Bob prefers Devonshire to Central, then we could allow Alice and Bob to switch if their submitted rankings indicated that these moves were consistent with their desires. There would be no incentive to lie.