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> While this isn't a surprising tradeoff for the Netherlands, what does surprise me is the size of the tradeoff they are willing to make. Almost eight percent o

> While this isn't a surprising tradeoff for the Netherlands, what does surprise me is the size of the tradeoff they are willing to make. Almost eight percent of the entire student body would be going to a not-first choice school as a result. (Using the numbers in the article) That's quite a hit. It is, but it needs to be balanced against the percentage of disappointed students in a regular, non-lottery system. The article doesn’t say what that is, unfortunately.

danielvf 8y ago
It's certainly true that the current state is better than a non-lottery system. That's not what the judge's decision changed though - it changed from preference+lottery with trades to preference+lottery without trades. This creates a strictly worse outcome for that school year, since only students who would mutually benefit from a trade would trade, and students who did nothing or could not trade would remain unchanged.
- fmihaila 8y ago
  > This creates a strictly worse outcome for that school year, since only students who would mutually benefit from a trade would trade, and students who did nothing or could not trade would remain unchanged. That's true. My understanding is that they did that for two reasons. The first was that a property of this particular algorithm is that mutually beneficial swaps are only possible if there is a third student placed at a third school who would also prefer one of the two being swapped, but whose school is not desirable, so he doesn't have a choice, which was deemed unfair (I don't know how I feel about this argument). The second was that allowing trades for this school year would encourage strategizing in the following years, which would lead to worse outcomes over time. These two things were addressed when they changed the lottery system once again.
nightcracker 8y ago
Figure 4 of the linked study (http://www.moniquedehaan.nl/wp-content/uploads/2016/08/schoolchoice2016july.pdf http://www.moniquedehaan.nl/wp-content/uploads/2016/08/schoo...) is very illuminating: https://imgur.com/a/Tjhqdfh https://imgur.com/a/Tjhqdfh Looking at that graph the decision seems very reasonable.

danielvf 8y ago

It's certainly true that the current state is better than a non-lottery system. That's not what the judge's decision changed though - it changed from preference+lottery with trades to preference+lottery without trades. This creates a strictly worse outcome for that school year, since only students who would mutually benefit from a trade would trade, and students who did nothing or could not trade would remain unchanged.

fmihaila 8y ago
> This creates a strictly worse outcome for that school year, since only students who would mutually benefit from a trade would trade, and students who did nothing or could not trade would remain unchanged. That's true. My understanding is that they did that for two reasons. The first was that a property of this particular algorithm is that mutually beneficial swaps are only possible if there is a third student placed at a third school who would also prefer one of the two being swapped, but whose school is not desirable, so he doesn't have a choice, which was deemed unfair (I don't know how I feel about this argument). The second was that allowing trades for this school year would encourage strategizing in the following years, which would lead to worse outcomes over time. These two things were addressed when they changed the lottery system once again.

nightcracker 8y ago

Figure 4 of the linked study (http://www.moniquedehaan.nl/wp-content/uploads/2016/08/schoolchoice2016july.pdf http://www.moniquedehaan.nl/wp-content/uploads/2016/08/schoo...) is very illuminating: https://imgur.com/a/Tjhqdfh https://imgur.com/a/Tjhqdfh Looking at that graph the decision seems very reasonable.