The Amsterdam court rules on school choice

Hessel Oosterbeek sends the following update on the school choice court case seeking to allow the exchange of school places that were allocated by a deferred acceptance algorithm with multiple tie breaking.  He writes: 

"Attached is a link to the decision of the judge in Amsterdam. Important considerations for the judge are that: i) trading would harm students who have a higher position on the waiting lists, and ii) allowing trade this year makes the system unusable in the future. The judge also writes that the rules were clear.

Overall it reads that the judge is well informed."

Google Translate allows you to make reasonable sense of the judge's decision in English...
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Here is a blog post, also in Dutch, but Google Translate does a good enough job so that you can see that this is a pretty detailed discussion of various algorithms, strategy-proofness, the judge's decision, etc. It seems that the public discussion is going on at a pretty high level: 
Schoolstrijd in Amsterdam
Waarom ruilen niet mag, ook niet als beide partijen er beter van worden
(School Fight in Amsterdam

Why should not change, even if both parties are better off)

School choice in Amsterdam goes to court over tie-breaking

Hessel Oosterbeek sends me this article in Dutch about the very current controversy playing out in Amsterdam over this year's school choice results:

Het beest in de Amsterdamse ouder is los,
which Google Translate renders as
The beast in Amsterdam's parent is loose

Some background to the current controversy can be found in a paper by Oosterbeek and his coauthors which was influential in the Amsterdam school choice design (which used student-proposing deferred acceptance with multiple tie-breaking):

"The performance of school assignment mechanisms in practice," by Monique de Haan, Pieter A. Gautier, Hessel Oosterbeek, and Bas van der Klaauw.

Abstract: "Theory points to a potential trade-off between two main school assignment mechanisms; Boston and Deferred Acceptance (DA). While DA is strategyproof and gives a stable matching, Boston might outperform DA in terms of ex-ante efficiency. We quantify the (dis)advantages of the mechanisms by using information about actual choices under Boston complemented with survey data eliciting students’ school preferences. We find that under Boston around 8% of the students apply to another school than their most-preferred school. We compare allocations resulting from Boston with DA with single tie-breaking (one central lottery; DA-STB) and multiple tie-breaking (separate lottery per school; DA-MTB). DA-STB places more students in their top-n schools, for any n, than Boston and results in higher average welfare. We find a trade-off between DA-STB and DA-MTB. DA-STB places more students in their single most-preferred school than DA-MTB, but fewer in their top-n, for n ≥ 2. Finally, students from disadvantaged backgrounds benefit most from a switch from Boston to any of the DA mechanisms"

The city of Amsterdam adopted multiple tie-breaking, with the consequence that some post-assignment trades now seem possible between students.  And this is where the beast in Amsterdam's parents (some of whom are lawyers) has been loosed. Here's Google Translate again, on the news story:

"Moreover, there is a side effect that parents can not stomach: a class can sit next to each other two children who are both disappointed in the school they were assigned, whereas if they would swap, both overjoyed to be made ​​with a spot on their favorite school. A child who is placed in a school where he really did not want it (tenth place on his preference list), through an exchange would nevertheless may still end up at No. 1. And yet you can not. There is, every year it again what in Amsterdam that the beast in the parent disconnect when it comes to the choice of school of the child.
...
"A father of a girl who wants to be very happy in music and dance, with a spot on the Geert Groot School, turned to Sprenkeling for an exchange. To facilitate this exchange, harnessed the lawyer with 32 other parents a lawsuit against the dome of high schools Osvo. The aim is to consider the new placement system this year as a test. Only next year should really not be exchanged. "

I understand from Hessel that a judge is expected to rule soon on whether families may exchange school places...