The downside of the DC school lottery

[Anonymous]

Anonymous wrote:

Anonymous wrote:

Anonymous wrote:The problem isn't that the lottery is poorly designed. The problem is that high-quality education should not be a scarce resource that is allocated by lottery in a first-world country.

I don't want more choices. I just want nicer things.

Then move to the suburbs.

Move to a rich “white flight” suburb where people use zoning laws to prevent density, keep housing prices cripplingly high, and create sprawl and traffic that makes all of us have long commutes so you can exclude people.

Fixed that for you.

Wouldn’t it be nice if you could afford it, Bethesda schools are all great

[Anonymous]

Anonymous wrote:

But the posts above about fixed number of seats are just missing the point.

we can take the posts above about “make all the schools better!!!” and draw an analogy to the NBA lottery.


While some of us are discussing how the lottery might be tweaked to improve it, the “schools all better” crowd is basically saying
“MAKE ALL THE PLAYERS BETTER ... IF WE HAD 100 KOBE BRYANTS IN EVERY LOTTERY THERE WOULD BE NO NEED FOR A LOTTERY!!!!!”

Well, yes, that is true. Noted.

Given limited resources, putting resources toward improving schools has better outcomes that putting resources toward fixing the lottery. (I think you are saying that too, no?) The analogy isn't Kobe Bryant, it's clean drinking water. Everybody should have it.

[Anonymous]

Anonymous wrote:

Anonymous wrote:

But the posts above about fixed number of seats are just missing the point.

we can take the posts above about “make all the schools better!!!” and draw an analogy to the NBA lottery.


While some of us are discussing how the lottery might be tweaked to improve it, the “schools all better” crowd is basically saying
“MAKE ALL THE PLAYERS BETTER ... IF WE HAD 100 KOBE BRYANTS IN EVERY LOTTERY THERE WOULD BE NO NEED FOR A LOTTERY!!!!!”

Well, yes, that is true. Noted.

Given limited resources, putting resources toward improving schools has better outcomes that putting resources toward fixing the lottery. (I think you are saying that too, no?) The analogy isn't Kobe Bryant, it's clean drinking water. Everybody should have it.

1. Yes we should direct resources into improving schools. The lottery is fun to talk about here but money should go to schools.
2. The analogy IS Kobe Bryant because the lottery apportions limited resources. Everyone can have clean drinking water (at least in cities who unlike Flint are not ruled by Republican governors that care more about billionaires’ tax cuts than healthy children. DC was the guinea pig for this corrosion problem. But now we know all about it.) But good schools are always going to be somewhat competitive to enter. There’s always going to be at least one school with more applicants than seats.

[Anonymous]

Anonymous wrote:

Anonymous wrote:

Anonymous wrote:

Anonymous wrote:The problem isn't that the lottery is poorly designed. The problem is that high-quality education should not be a scarce resource that is allocated by lottery in a first-world country.

I don't want more choices. I just want nicer things.

Then move to the suburbs.

Move to a rich “white flight” suburb where people use zoning laws to prevent density, keep housing prices cripplingly high, and create sprawl and traffic that makes all of us have long commutes so you can exclude people.

Fixed that for you.

Wouldn’t it be nice if you could afford it, Bethesda schools are all great

?? DC is more expensive than Bethesda.

[Anonymous]

Anonymous wrote:

Anonymous wrote:

Anonymous wrote:

But the posts above about fixed number of seats are just missing the point.

we can take the posts above about “make all the schools better!!!” and draw an analogy to the NBA lottery.


While some of us are discussing how the lottery might be tweaked to improve it, the “schools all better” crowd is basically saying
“MAKE ALL THE PLAYERS BETTER ... IF WE HAD 100 KOBE BRYANTS IN EVERY LOTTERY THERE WOULD BE NO NEED FOR A LOTTERY!!!!!”

Well, yes, that is true. Noted.

Given limited resources, putting resources toward improving schools has better outcomes that putting resources toward fixing the lottery. (I think you are saying that too, no?) The analogy isn't Kobe Bryant, it's clean drinking water. Everybody should have it.

1. Yes we should direct resources into improving schools. The lottery is fun to talk about here but money should go to schools.
2. The analogy IS Kobe Bryant because the lottery apportions limited resources. Everyone can have clean drinking water (at least in cities who unlike Flint are not ruled by Republican governors that care more about billionaires’ tax cuts than healthy children. DC was the guinea pig for this corrosion problem. But now we know all about it.) But good schools are always going to be somewhat competitive to enter. There’s always going to be at least one school with more applicants than seats.

Good schools are not a fundamentally limited resource, which is a way of saying that making one school better doesn't make another worse. If the pool of resources is bigger apportioning them so that everyone gets something is easier.

[Anonymous]

Anonymous wrote:

Anonymous wrote:
I guess the take home here from this thread is: yes, reasoning about probability and stochastic processes is hard.

No, the takeaway is you are a stubborn person. You got an idea into your head. You find it impossible to believe your idea is wrong, so you go on all sorts of logical excursions -- and throw in insults to those who try to set you straight, to boot.

Your logical fallacy is in this paragraph, in the bolded part:

What you want to do instead is calculate the VARIANCE of outcomes with 1 roll or 100 rolls for 100 schools. You are correct that the number of seats does not change so the number of students given a seat does not change. What changes is the ordering and the waitlist positions. To see this, look at the kid with the lowest 1-roll master number. They are last on all their waitlists. That situation does not happen if there are multiple rolls.

Having more rolls doesn't affect the variance of outcomes. It affects the variance of the numbers used to determine the outcomes. With a single roll you get a linear distribution, with more rolls you get more of a normal distribution. But when you take those numbers are rank the participants, the outcome is the same: someone is first, someone is last, and only some of the participants get a seat because there are more participants than seats.

The ordering and waitlist positions aren't important, what's important is whether you get a seat or not. It does you no good to have a good waitlist position if the waitlist doesn't move. You seem to be obsessed with the idea that the lottery lets those with good number "hoard" good fortune, which could more equitably be distributed to the less fortunate. But that's not how it works. Everyone gets either one seat, or no seat. There is no way to distribute them more granularly.

I'm assuming you're obsessing over this because you got a bad lottery number and just can't accept that you're unlucky rather than the system being broken. I'm sorry you got a bad number, better luck next time. But this is a strange thing to obsess over. As another poster pointed out, the lottery is one of the best-functioning things in all of public education in DC. And it has consistently gotten better in recent years. If you want to get upset, there are lots of bigger issues to get upset about.

“Linear distribution” (not a thing; try Bernoulli distribution for a coin or discrete uniform for a die)
“More normal distribution” (?)
“One seat” (ignoring waitlists)

Again: I recommend a stochastic processes class. I think where you’re being tripped up is that a statistical model should be thought of as having an ensemble of outcomes. This idea is what links the variance of die rolls with the variance of outcomes. Cheers!

[Anonymous]

Anonymous wrote:

Anonymous wrote:

Anonymous wrote:
I guess the take home here from this thread is: yes, reasoning about probability and stochastic processes is hard.

No, the takeaway is you are a stubborn person. You got an idea into your head. You find it impossible to believe your idea is wrong, so you go on all sorts of logical excursions -- and throw in insults to those who try to set you straight, to boot.

Your logical fallacy is in this paragraph, in the bolded part:

What you want to do instead is calculate the VARIANCE of outcomes with 1 roll or 100 rolls for 100 schools. You are correct that the number of seats does not change so the number of students given a seat does not change. What changes is the ordering and the waitlist positions. To see this, look at the kid with the lowest 1-roll master number. They are last on all their waitlists. That situation does not happen if there are multiple rolls.

Having more rolls doesn't affect the variance of outcomes. It affects the variance of the numbers used to determine the outcomes. With a single roll you get a linear distribution, with more rolls you get more of a normal distribution. But when you take those numbers are rank the participants, the outcome is the same: someone is first, someone is last, and only some of the participants get a seat because there are more participants than seats.

The ordering and waitlist positions aren't important, what's important is whether you get a seat or not. It does you no good to have a good waitlist position if the waitlist doesn't move. You seem to be obsessed with the idea that the lottery lets those with good number "hoard" good fortune, which could more equitably be distributed to the less fortunate. But that's not how it works. Everyone gets either one seat, or no seat. There is no way to distribute them more granularly.

I'm assuming you're obsessing over this because you got a bad lottery number and just can't accept that you're unlucky rather than the system being broken. I'm sorry you got a bad number, better luck next time. But this is a strange thing to obsess over. As another poster pointed out, the lottery is one of the best-functioning things in all of public education in DC. And it has consistently gotten better in recent years. If you want to get upset, there are lots of bigger issues to get upset about.

“Linear distribution” (not a thing; try Bernoulli distribution for a coin or discrete uniform for a die)
“More normal distribution” (?)
“One seat” (ignoring waitlists)

Again: I recommend a stochastic processes class. I think where you’re being tripped up is that a statistical model should be thought of as having an ensemble of outcomes. This idea is what links the variance of die rolls with the variance of outcomes. Cheers!

Linear distribution: when every outcome has exactly the same probability, the graph of outcomes vs. probabilities is a straight line.

"More normal distribution" -- a distribution that more closely resembles a normal distribution.

Not sure what the third comment means.

Why don't you try addressing my argument instead of attacking my choice of words?

[Anonymous]

Your argument is flawed because your understanding of math is flawed, as shown in the words you use to describe the incomplete concepts.

If you don’t understand at this point after four different explanations then you don’t want to understand. ¯\_(?)_/¯

[Anonymous]

Anonymous wrote:

Anonymous wrote:

Anonymous wrote:

Anonymous wrote:

Anonymous wrote:The problem isn't that the lottery is poorly designed. The problem is that high-quality education should not be a scarce resource that is allocated by lottery in a first-world country.

I don't want more choices. I just want nicer things.

Then move to the suburbs.

Move to a rich “white flight” suburb where people use zoning laws to prevent density, keep housing prices cripplingly high, and create sprawl and traffic that makes all of us have long commutes so you can exclude people.

Fixed that for you.

Wouldn’t it be nice if you could afford it, Bethesda schools are all great

?? DC is more expensive than Bethesda.

in some parts but not really where the schools suck and it pales in comparison to affordability. There simply aren't many cheap apts that go to Whitman or Churchill. DC has more options

[Anonymous]

Anonymous wrote:

Anonymous wrote:

Anonymous wrote:

Anonymous wrote:
I guess the take home here from this thread is: yes, reasoning about probability and stochastic processes is hard.

No, the takeaway is you are a stubborn person. You got an idea into your head. You find it impossible to believe your idea is wrong, so you go on all sorts of logical excursions -- and throw in insults to those who try to set you straight, to boot.

Your logical fallacy is in this paragraph, in the bolded part:

What you want to do instead is calculate the VARIANCE of outcomes with 1 roll or 100 rolls for 100 schools. You are correct that the number of seats does not change so the number of students given a seat does not change. What changes is the ordering and the waitlist positions. To see this, look at the kid with the lowest 1-roll master number. They are last on all their waitlists. That situation does not happen if there are multiple rolls.

Having more rolls doesn't affect the variance of outcomes. It affects the variance of the numbers used to determine the outcomes. With a single roll you get a linear distribution, with more rolls you get more of a normal distribution. But when you take those numbers are rank the participants, the outcome is the same: someone is first, someone is last, and only some of the participants get a seat because there are more participants than seats.

The ordering and waitlist positions aren't important, what's important is whether you get a seat or not. It does you no good to have a good waitlist position if the waitlist doesn't move. You seem to be obsessed with the idea that the lottery lets those with good number "hoard" good fortune, which could more equitably be distributed to the less fortunate. But that's not how it works. Everyone gets either one seat, or no seat. There is no way to distribute them more granularly.

I'm assuming you're obsessing over this because you got a bad lottery number and just can't accept that you're unlucky rather than the system being broken. I'm sorry you got a bad number, better luck next time. But this is a strange thing to obsess over. As another poster pointed out, the lottery is one of the best-functioning things in all of public education in DC. And it has consistently gotten better in recent years. If you want to get upset, there are lots of bigger issues to get upset about.

“Linear distribution” (not a thing; try Bernoulli distribution for a coin or discrete uniform for a die)
“More normal distribution” (?)
“One seat” (ignoring waitlists)

Again: I recommend a stochastic processes class. I think where you’re being tripped up is that a statistical model should be thought of as having an ensemble of outcomes. This idea is what links the variance of die rolls with the variance of outcomes. Cheers!

Linear distribution: when every outcome has exactly the same probability, the graph of outcomes vs. probabilities is a straight line.

"More normal distribution" -- a distribution that more closely resembles a normal distribution.

Not sure what the third comment means.

Why don't you try addressing my argument instead of attacking my choice of words?

Could you two geniuses please just take this offline and agree to meet up in person and drop your pants to see whose mathematical credentials are bigger?

[Anonymous]

Anonymous wrote:I think where your confused is you think that someone with a high lottery number gets into all of their choices, and that someone else is kept from getting those seats. That's not how it works. Someone with a high lottery number gets into their first choice.

Changing the way the draw is done doesn't change the number of seats. The only question to ask about a system is whether once it's all done, are there any two people who would be willing to trade with each other and each be happier? If so, then the system is flawed.

The current system is designed so that it never happens that mutually beneficial trades exist, so long as people put in their true preferences. That also means that strategizing or gaming is impossible, the best outcome for any individual is to put in their true preference.

No, it means someone entering the lottery didn't use it correctly.

[Anonymous]

Anonymous wrote:

Anonymous wrote:
This. Every year there is at least one poster on DCUM who posts something like this. Because your very basic understanding is clearly superior to the Nobel prize winning algorithm designed to prevent gaming and reward only true preference.

This is the Pete Buttigieg effect: people who don’t know Harvard types think everyone should be super-impressed by them. While people who are or know Harvard types are capable of asking smart questions about problems and having a conversation about pros and cons.

This is absolutely true. The OP did not do this, though; she suggested a system that has been used in the past, and discarded in favor of the current, more efficient system.

In essence, the Op is asking, "Hey, you know hat thing that we used to have, that worked worse than this? Hows about we do that again? Here's a bunch of reasons that have already been discredited that we should do so."

[Anonymous]

Anonymous wrote:

Anonymous wrote:

Anonymous wrote:I do not understand why there are so many slots per entry. Does it increase or decrease your chances of getting in if you do not use all the slots? And why do people even put in slots that they don’t really want?

It increases your chances of getting into a school if you can list more schools. It will not affect how good your number is. But we matched with our #12 choice. If we could only list 10, we would have had no match. We did really want it, just not as much as we wanted the 11 above it. But we enrolled and it has been good so far.

I have a hard time believing that there are 12 schools that are that much better than an IB for a 3 year old when you take into account commutes. There aren’t 12 good public/charter MS options in the entire city. Six is a more reasonable number.

No one selects a lottery school because of PK3 (unless they're already planning on leaving). They choose the school because of the elementary school, and the middle school feeder rights, and the high school feeder rights, and the likelihood that those feeder rights won't change for 14 years.

[Anonymous]

Anonymous wrote:

But the posts above about fixed number of seats are just missing the point.

we can take the posts above about “make all the schools better!!!” and draw an analogy to the NBA lottery.


While some of us are discussing how the lottery might be tweaked to improve it, the “schools all better” crowd is basically saying
“MAKE ALL THE PLAYERS BETTER ... IF WE HAD 100 KOBE BRYANTS IN EVERY LOTTERY THERE WOULD BE NO NEED FOR A LOTTERY!!!!!”

Well, yes, that is true. Noted.

But we'd need more prosecutors and sex crimes investigators. There are trade-offs everywhere.

[Anonymous]

I have no degree in math, and I only understood a small fraction of what the two ner . . . uh, PPs were arguing about. But, I have a question for OP:

There are a finite number of "good" school slots in DC, (let's say 100), and more kids (let's say 150) than good seats. Op, why if your proposed lottery system better than the existing one in that scenario? More specifically, why is your system better for the 100 who get the good seats, and/or why is it better for the 50 who don't?

Not the math behind it - how does it improve the scenario for those 150 kids?