
Model Metropolis - tekromancr
https://logicmag.io/06-model-metropolis/
======
Lazare
The article was interesting; I'd never heard of Forrester before.

What I found interesting though, is the fact that the article never seemed to
get into the question of whether he was _right_. Is that because the author
considered it too obvious to warrant discussion, or because he didn't think it
was relevant?

The tone of the piece feels like it's intended as a takedown, but the only
actual criticism I noticed was here:

> we have decades of real-world evidence that demonstrates the disastrous
> costs of the “counterintuitive” anti-welfare agenda

But this came immediately after a section tracing this line of thinking back
to some of the 20th centuries most respected thinkers, and after stating that
this was now the default mode of analysis for policy wonks.

It reads like the author thinks they're administering the final blow after
building up a damning case, and yet...

~~~
Jtsummers
I agree. I think the real conclusions ought to be (non-exhaustive):

Keep the model's assumptions in mind when making decisions based on it.

Always remember that it's a model, and consequently always wrong (as measured
against reality).

All models have to be fine-tuned over time, especially dynamic models (where
the system being modeled is itself subject to change in structure,
consequently invalidating the model).

=====

If you emphasize that the model is just a model, and its assumptions (both for
excluded factors and included ones), then you can make reasonable decisions
guided by the model. If you fail to do that, you'll start to believe the
reductionist model and make flawed decisions.

~~~
hoaw
Which is essentially the whole argument of the article. For example as
summarized in the last paragraph:

"Expert knowledge, of course, has an important place in democratic
deliberation, but it can also cut people out of the policy process, dampen the
urgency of moral claims, and program a sense of powerlessness into our public
discourse."

------
shittyadmin
While I think I'm somewhat in agreement with this, this post seems to be
making some claims without backing them up at all:

> To Forrester, low-income housing was an especially egregious example of a
> “counterproductive” urban program. According to the model, these programs
> increased the local tax burden, attracted underemployed people into the
> city, and occupied land which might otherwise have been put to more
> economically healthy uses. Housing programs aimed at improving the condition
> of the underemployed, Forrester warned, “increased unemployment and reduced
> upward economic mobility” and would condemn the underemployed to lifelong
> poverty.

Where's the data to suggest this is false? In fact it seems to me like
something that may hold true in data, even if deeper causes are at fault.

> but we have decades of real-world evidence that demonstrates the disastrous
> costs of the “counterintuitive” anti-welfare agenda

... with no evidence provided?

Overall they actually seem like pretty reasonable theories at face value and
calling them crap without evidence doesn't seem like a good solution if
there's a problem with them.

~~~
ruytlm
Shouldn't the burden of proof should be on Forrester's model to prove that it
is true?

As I understand it, this article is implying that Forrester's model
incorporated those as base truths, without particularly rigourous evidence to
support them - hence the comment about his lack of social science credentials.
(Whether Forrester actually had evidence to support his model I do not know,
as I have not dug deeper.)

~~~
shittyadmin
It's a bit like saying that math is wrong though - logically speaking, low-
income housing has costs associated with it in more ways than one, not just
housing but for law enforcement, education, etc, all of which will clearly
have demand go up and income won't go up as much as if someone who had more
money were to live in that city instead. Depressing, perhaps, but factual.

If that basic piece of math is wrong, it needs to be proven - how do low
income households contribute more than their fair share of city revenue for
example? Does homelessness cause law enforcement issues to increase to a
greater amount than low-income housing? Do low-income households produce more
future earners that add up better for the city?

We need some data here to show that the basic economics of this don't actually
add up if that's the claim being made, because from a basic economics
perspective the argument logically and mathematically follows.

~~~
akiselev
That entire argument is dependent on the assumption that low income housing
_attracts_ people instead of responding to the needs of the local community.
Logically, areas that require low income housing are very likely to have a
relatively high cost of living to begin with and economic mobility has not
changed enough in the last few decades to account for the increase in the
homeless population in concentrated metropolitan areas. Despite the great
recession, homelessness rates have fallen by almost 20% since 2000 but anyone
who has lived in LA, SF, NYC, Portland, or Seattle can tell you that on the
ground, bare facts dont tell the whole story.

No doubt locating the actual sweet spot is impossibly complicated and it
depends on the region but naive logic will not solve this problem, only
experience and data will.

~~~
AnthonyMouse
> That entire argument is dependent on the assumption that low income housing
> _attracts_ people instead of responding to the needs of the local community.

Not necessarily. It could cause/allow people to stay who would otherwise have
left, to much the same effect.

You also have the opposite problem, because the same land could have been used
for market rate housing, so you've prevented entry by new middle income people
who could have brought more resources into the community.

~~~
dashundchen
Forester's model of public housing here is looking only in terms of cost, and
not what it can provide.

A very large assumption lies here: >Housing programs aimed at improving the
condition of the underemployed, Forrester warned, “increased unemployment and
reduced upward economic mobility” and would condemn the underemployed to
lifelong poverty.

and completely ignores the benefits that public housing in a city can provide.

That is, housing can provide security and meet a basic need for those who may
be struggling with many basic needs (food, employment, education, health).

Having this need met allows recipients to focus energy and money normally
spent on housing on other issues, potentially reducing other costs and
allowing them to progress out of poverty.

I think we can see the evidence there are benefits in examples at the furthest
end of poverty - homelessness. Many cities found that it is cheaper to house
the homeless and provide them social services, than to ignore them and treat
the effects of homelessness issues (police and jail time for crimes, from
desperation or untreated mental illness, emergency medical services for
treating overdoses etc).

This is not even getting to the question of the purpose of government - it is
not a business trying to achieve maximum profit, so why should it be seeking
to drive out low-income residents?

[https://thinkprogress.org/leaving-homeless-person-on-the-
str...](https://thinkprogress.org/leaving-homeless-person-on-the-
streets-31-065-giving-them-housing-10-051-3107834a8632/)

~~~
shittyadmin
> This is not even getting to the question of the purpose of government - it
> is not a business trying to achieve maximum profit, so why should it be
> seeking to drive out low-income residents?

Can I move somewhere that _is_ run like a business trying to maximize profit?
I think I'd far prefer it to my wasteful city...

~~~
dashundchen
Let's say every local government in a country operated that way - all doing
their best to maximize attractions for the rich (and 'profit') and limit
attractions/spending for the poor.

Obviously poor people must move somewhere, so the end result is society has
just conspired to make their poverty and misery government's permanent goal.

I think this attitude is fairly common in the US. Look how many people think
punishments or burdens need to be attached to welfare, without any proof of
fraud reduction. Things like mandatory drug testing, work requirements,
restrictions to what TANF and SNAP and be spent on.

~~~
shittyadmin
Perhaps "profit" isn't the best way to put it, but "wellbeing per dollar" in
some way - ultimately a measurable optimization factor of some sort needs to
be decided on and used.

Instead we see cities without any sort of optimization, repeatedly trying
failed ideas, flushing tax dollars down the toilet. "This clearly isn't
working, let's just keep doing it" ought to be the slogan for many midsize
cities.

~~~
sjg007
We already optimize for wellbeing per dollar.

~~~
shittyadmin
You're joking, right? Broken transit systems, barely maintained roads, large
backlogs of intersections that need lights leading to safety incidents even
deaths, planners that accept everything a developer or NIMBY can say... No, we
don't optimize for shit except perhaps councilors pocketbooks and re-election.

We _wish_ these systems were optimized, but they're not. If they were, we'd at
least see pushes to get people to live closer to work, the rejection of NIMBYs
in favor of multiunit developers in central areas while in distant areas we'd
see rejection of developers in favor of improved transit.

Many areas in my city have terrible access by car or public transit because
the city has kept pushing back road and transit improvements while allowing
developers to keep going. It's gotten so bad a few developers were offering to
do road widening for the city on an interest free loan as their property
values were taking a hit due to a reputation for long commutes - unfortunately
that fell through even, it's a mess, a completely unoptimized mess.

------
ruytlm
> "Even though Forrester had no expertise in urban affairs—or in social
> science more generally—Collins agreed that a collaboration could prove
> fruitful."

This is one of the most interesting sentences to me. I have long been
convinced that the efforts to reduce behaviour and models down to pure
numbers, and disregard the human element - whether willfully or through
ignorance or naivety), are more harmful than we think.

I think we are seeing similar things with how the attempt to 'personalise'
services like news by crunching user behaviour into 'predictive' algorithms
has led to the rise of echo chambers and fake news.

Or, I suppose you could consider the attempts to reduce bundles of derivatives
to simple algorithms, that largely led to the 2008 financial crisis.

It seems a particularly human thing to assume we know far more about what's
going on than we actually do.

------
danbolt
My friends and coworkers often speak a lot of praises about the
survival/industrial game _Factorio_. In the game, pollution from the player’s
generators attract hostile creatures that one has to manage. The player can
use renewable energy an option, but it’s not as easily productive or scalable
as other sources of power.

I haven’t played the game, but I always thought of the pollution/conflict
dynamic and renewables being more safe (but harder to get right) as a
statement on environmental policy.

~~~
aero142
I think the actual game is much harsher than this. You play as the main
character and the game is really just about expanding the factory for the sake
of expanding the factory. It serves no purpose other than making the factory
bigger. You might be able to produce a little less pollution with solar but at
the end, the game is about expanding the factory. You will cut down the
forests, and pollute the environment, and pave over the beautiful landscape
and the remove the homes of the natives that stand in your way. Why? Because
it's what you do. It's factorio. It's slightly subtle, but not really. I think
everyone realizes this is the backdrop of the game but you just keep building,
and paving and polluting, because it's Factorio. It feels like it should be
some moral lesson, I'm not sure what it is though. You just keep doing stuff
and having fun.

~~~
joshu
er, there is an endgame. the rocket.

~~~
aero142
Yes, yes. Rocket is good. But what about second rocket?

------
jonathankoren
Adam Curtis talked about Forester and the study of “cybernetic systems” (to
use the contemporary term) in general, in episode 2 of “All Watched Over By
the Machines Of Loving Grace” [0].

The core argument (which is alluded to in the Logic Magazine article) is that
in the 1960s when computers were beginning to be integrated into companies and
governments, there was a strong desire to have the computer solve all the
world’s problems. Of course, the problems were not well understood (and still
often aren’t), while at the same time the computers were woefully
underdeveloped. Therefore simplifications were made so that the computer could
calculate something that looked somewhat reasonable. Of course the models were
symplistic, and the data encoding symplistic and biased as well. But hey, the
computer “solved” the problem, and as we all know, “Computers don’t make
mistakes.” Eventually (and Forrester encouraged) the simplistic world was
confused for an actual complete description of the real one. Most damningly,
industrial leaders and politicians, started trying to make people and society
fit the simplistic model, instead of improving the models to better fit
society. Why? Well, there was a computer model made by Very Smart Men(tm), and
it gave cover for what was already decided, so it must be right.

It’s as if the proverbial dairy farmer that received the report that begins,
“Suppose you have a spherical cow...”, started selective breeding and cutting
his cows to optimize for sphericality, as opposed to milk production, because
the report says “spherical cows.”

It’s a similar pattern we’re seeing play out with ML, where the assumption is
that the classifier is correct regardless of its actual performance.

[0]
[https://archive.org/details/AllWatchedOverByMachinesOfLoving...](https://archive.org/details/AllWatchedOverByMachinesOfLovingGraceEpisode2TheUseAndAbuseOfVegetationalConcepts)

------
AbrahamParangi
“Using this rhetorical tactic, the conservative speaker can claim that they
share your social goal, but simultaneously argue that the means you are using
to achieve it will only make matters worse.”

I think this line in particular really demonstrates the resistance to
ideological debate on the left (to say nothing of resistance on the right
which I think has a different character). It’s like, these ideas that aren’t
already part of your ideology are discredited because you assume they come
from a place of bad-faith.

If you refuse to engage with someone’s ideas (who supposedly wants to solve
the same problems you do!) because you’ve already assumed they’re evil- that
seems like a pretty dangerous mindset to me.

------
pasta
At the moment I am playing 'Cities: skylines' which it one of the best city
cims at the moment imho.

But the real question is: does it simulate what we know or what works best?

Ofcourse I think it simulates what we know which might not be the best for
people.

When you read the works of Christopher Alexander you will get the feeling that
we need to redesign our areas. And this is not what a sim simulates..

------
33a
I agree with the general sentiment of this sort of objection, but where it
goes off the rails is the generalization to all sorts of modeling. If you
think the model and it's assumptions are wrong why not go build a better
model? That's the whole point of the scientific method after all.

~~~
logicchains
>If you think the model and it's assumptions are wrong why not go build a
better model?

The better model may be intractable to fit (so complex that we lack enough
data to train it). Or, it may be fittable but not easy to understand, e.g. a
neural network model.

~~~
Fomite
This. I work with models that are considerably simpler than "200 equations and
150 parameters" and we run into non-identifiability problems _all the time_.

------
int_19h
> As one moved down the class ladder in the urban dynamics model, classist
> assumptions about the urban poor piled up: birth rates were higher

Why is this controversial, or, for that matter, an assumption? There's plenty
of studies demonstrating correlation between income and fertility... or are
they implying that the correlation is only meaningful nation-wide, not within
any particular city?

~~~
Lazare
It was puzzling. I suppose the argument isn't that the assumption was
factually wrong, but morally wrong?

~~~
hoaw
No, it is arguing that it is factually wrong based on prejudice. Most
obviously that the groups negative factors aren't inherent and their
contributions aren't valued.

~~~
int_19h
That would be worded very differently than it actually is in the article. It
specifically states that the very notion that urban poor have higher
birthrates is _in and of itself_ a "classist assumption", not because other
factors are omitted.

------
acoye
LGR just released a video retrospective on the subject, 30 years later. You
can find it here :
[https://www.youtube.com/watch?v=TrScy1icWjI](https://www.youtube.com/watch?v=TrScy1icWjI)

------
colinb
Does anyone know if there's a strong link between Forrester and Donella
Meadows, of Thinking in Systems? I'm reading that book after seeing it praised
more than once on HN.

Meadows provides lots of food for thought, and I think I could make my
workplace better if I figured out how to apply some of the ideas she
expresses. I'm not convinced that all of her reasoning is very rigorous, and I
suppose that matches the feelings of the author of this article, not that I
think he does a great job of rigor either. Once the fine article extended its
ideas from city planning to no platforming, without apparent irony, or data, I
got the yawn.

~~~
Jtsummers
She worked with Forrester’s group in the late 60s/early 70s. So there’s a
direct connection.

------
mwkaufma
For more on Jay Forrester's philosophy and influence on politics,
internationally, check out the All Watched Over by Machines of Loving Grace
documentary series by Adam Curtis.

------
EricE
The vast majority of social programs when played out to their natural
conclusions do make problems far worse.

Just look at the mayhem easy to obtain government backed student loans have
caused in "higher" education - skyrocketing tuition and a bachelors degree
being worth about the same as a high school diploma was in the 80's. But now
with crippling debt for new graduates.

Yeah! But we are improving things!

~~~
so33
>Just look at the mayhem easy to obtain government backed student loans have
caused in "higher" education - skyrocketing tuition and a bachelors degree
being worth about the same as a high school diploma was in the 80's. But now
with crippling debt for new graduates.

This is a problem that, as far as I can tell, exists mostly in America. I
doubt this is a problem in European countries where tuition is mostly free or
extremely low cost to begin with.

Maybe the key for effective social programs is not to apply a bandaid but to
fix the root cause.

