[HN Gopher] Schelling's Model of Segregation
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       Schelling's Model of Segregation
        
       Author : thunderbong
       Score  : 36 points
       Date   : 2022-01-09 16:23 UTC (6 hours ago)
        
 (HTM) web link (nifty.stanford.edu)
 (TXT) w3m dump (nifty.stanford.edu)
        
       | civilized wrote:
       | EDIT: given that the model was developed in 1971, I think some of
       | the below should be reconsidered. But I will leave it unaltered
       | so that the thread discussion continues to make sense.
       | 
       | -----
       | 
       | I don't think it's a very insightful model, because I don't think
       | people are segregating because they want some % of their
       | neighbors to look like them. And even if they do, I think the
       | tendency toward segregation is pretty trivially obvious and
       | doesn't require a fancy agent based model to prove, although I'm
       | sure it's fun to fiddle with the parameters and see what happens.
       | 
       | Hypotheses I'd look at first: perhaps they want to live near
       | their relatives, who look like them, or they might only be able
       | to afford a certain neighborhood, which when combined with race-
       | class correlations reinforces segregation. Or there could be
       | inertia from a past time when explicit preferences existed.
       | 
       | Explicit desire to live near a certain % of same skin color is
       | really not the first hypothesis I'd reach for. And even if it
       | _is_ true, is it hard to see how segregation would result from
       | this?
        
         | DennisP wrote:
         | I don't think the point of a model like this is so much "this
         | is a full description of how the real world works," but "if you
         | make this assumption, then here's how it works out." It's
         | interesting when the result isn't what you'd naively expect.
         | 
         | A lot of people did find this particular model interesting. It
         | might seem that if segregation is due to preferences, then when
         | you see near-complete segregation it's because people preferred
         | to almost completely avoid people who don't look like them. But
         | actually, a relatively mild preference to just avoid being in
         | the minority is sufficient to make neighborhoods almost
         | completely segregated. That's true even if everyone actually
         | preferred being in mixed neighborhoods (as long as they weren't
         | in the minority).
         | 
         | Whether people actually do avoid being in the minority is a
         | separate question. But if were get some data saying that's the
         | case, then that would be sufficient to explain segregation.
        
         | mgraczyk wrote:
         | If the other factors are highly correlated with % of people in
         | a group, then this simple segregation model still makes some
         | sense.
         | 
         | Say group A has preferences for unmodeled factors that are
         | strongly correlated with the % of people living in an area who
         | are in group A. Think whole foods nearby, yoga studio, asian
         | fusion restaurant. All the stuff in the SF marina neighborhood.
         | As long as preferences are the same within the group, then
         | these external factors can be represented by the % of people in
         | group A.
         | 
         | This doesn't account for price and income though, which are
         | obviously important.
        
           | civilized wrote:
           | I just think it's fairly obvious that if people prefer to
           | live in places that would cause them to be segregated, then
           | they will be segregated. Not sure what the model adds to
           | this. Its parameters aren't a helpful guide to the underlying
           | reality.
        
             | mgraczyk wrote:
             | This model gives you numbers. It takes you from the very
             | vague: "differences in between-group preferences can cause
             | segregation" to something concrete. "X difference in
             | between group preference for Y will lead to Z-level
             | segregation." And X is surprisingly small for a given Z.
        
               | civilized wrote:
               | But there's no way to estimate the particular X in _this_
               | model in the real world, and the notion that that X is
               | the actual driver is just a bare possibility among
               | others, not really argued for or evidenced.
               | 
               | If you made a model where groups have different
               | preferences for "amenities" (nearby relatives, parks,
               | yoga studios) that would at least represent a more
               | plausible hypothesis. Although the parameters would still
               | be impossible to estimate.
               | 
               | I get what you're saying though. Broadly speaking it
               | might be theoretically interesting to set up various
               | quantitative models for the XYZ chain.
        
         | nerdponx wrote:
         | It might be an outdated model of segregation? Maybe it explains
         | the origins of segregated suburbs in the 1940s, but doesn't
         | explain its persistence into the 2020s.
        
           | asiachick wrote:
           | I guess it depends on what you mean by "explain". Any small
           | tendency is enough to cause segregation. Want to live near
           | relatives. Want to live near grocery store that caries your
           | ancestors cuisine's ingredients. etc...
        
             | civilized wrote:
             | Relatives plus culture seems like more than enough to do
             | it, no matter how egalitarian or "antiracist" the local
             | politics.
        
           | nine_k wrote:
           | Segregation is not limited to places where people choose to
           | live.
           | 
           | Large amounts of (self-)segregation are easy to observe in
           | any mixed social setting, such as social networks (within
           | them, across them), communities of whatever practice,
           | scientific schools, etc.
        
             | nerdponx wrote:
             | Good point, and in those contexts the model seems to more
             | or less line up with what I personally observe.
        
           | civilized wrote:
           | I think this is probably right.
        
       | brent_noorda wrote:
       | When the "similar" setting is even a little bigger than the
       | minority setting, it is hard to achieve satisfiaction. For
       | example, if the minority color is at 10% but satisfaction
       | requires 15%, then you can't find satisfaction. This tool shows
       | that the absolute fastest way to be satisfied is to not care
       | about the color of your neighbor. IE, the way to societal
       | happiness is to be color blind.
        
         | shadowgovt wrote:
         | And then the relevant question becomes "How does one change
         | human behavior and expectations?" That's an extremely non-
         | trivial problem.
        
         | uoaei wrote:
         | Maybe not color-blind, but universally color-tolerant.
        
           | Breazy wrote:
        
       | notRacistSir wrote:
        
       | seanhunter wrote:
       | There's a very elegant explanation of the model by Tim Harford of
       | BBC's "More or Less" https://www.youtube.com/watch?v=JjfihtGefxk
        
       | [deleted]
        
       | nine_k wrote:
       | The demo also shows a spectacular phase transition.
       | 
       | Make a mix like 10% / 90%, set tolerance to 50%. Even though some
       | clusters form, a lot of unsatisfied dots keeps wandering around
       | indefinitely, because there are not enough contiguous free areas.
       | 
       | Then change the tolerance to 51%, the smallest amount past 1/2.
       | Very-very quickly clusters form and motion stops; the segregation
       | is complete and stable.
        
       | throwaway894345 wrote:
       | I'm not sure if this is related or not, but another explanation
       | may simply be convenience. If you're an immigrant, you might want
       | to live in a place where you can easily buy ingredients to make
       | your native cuisine, which implies a mild clustering force. It
       | doesn't mean you prefer to be around people of your own ethnicity
       | _per se_. Probably more powerfully, you might want to be in a
       | place that shares your values, irrespective of ethnicity;
       | however, values probably correlate a bit with ethnicity, and thus
       | you end up segregating.
       | 
       | With respect to wealth, you probably prefer to live in a place
       | that maximizes value/money, which probably means living among
       | other people in a similar socioeconomic context (economies of
       | scale come into play when you have a lot of people with similar
       | socioeconomic statuses in a small area).
       | 
       | So as always, we need to think critically rather than concluding
       | "prejudice" at the first sign of disparity.
        
       | zamfi wrote:
       | There is another fantastic explanation (an "exploitable
       | explanation") by Nicky Case of this same phenomenon here:
       | https://ncase.me/polygons/
       | 
       | Interactive, web-based, explained. Highly recommended.
        
         | csense wrote:
         | Nicky Case's simulation is great and fun, but I think she
         | reaches the wrong conclusion.
         | 
         | Her takeaway is this (in my words, not hers): "Diversity is
         | good, therefore we should alter our behavior to increase
         | diversity."
         | 
         | My takeaway is the opposite (again, my own words): "Segregated
         | communities may arise in a decentralized way through the free
         | choices of people optimizing for individual preferences for
         | homogeneous communities. Engineering a system to promote
         | diversity may cause harm. Such an engineered system must, by
         | definition, pressure or force people to make a different choice
         | than they freely would."
        
         | crackercrews wrote:
         | Nice interactives. The framing seems flawed since all
         | preference is referred to as a "bias".
         | 
         | > Small individual bias can lead to large collective bias.
         | 
         | There are many reasons people might want to live near some
         | other people who are similar to themselves. Some are purely
         | practical, like language and food. It is not clear how much of
         | the total preference is rooted in these sorts of practical
         | realities as opposed to "bias" that would not exist in an ideal
         | world. Referring to all preferences as biases strikes me as
         | sloppy.
        
           | civilized wrote:
           | > Referring to all preferences as biases strikes me as
           | sloppy.
           | 
           | It would be sloppy if it were not deliberate.
           | 
           | I noticed nobody was accused of gentrification in this
           | simulation.
        
             | crackercrews wrote:
             | I was trying to be generous. Perhaps I overshot.
        
         | civilized wrote:
         | It's interesting how the two types in the simulation are said
         | to be "happier to live in a diverse environment" but their only
         | preference that leads to actual behavior is "when I'm in a 1/3
         | minority or less I'm unhappy and have to move".
         | 
         | Further down, when the shapes show their preference for
         | neighborhood diversity in actual behavior, you get diverse
         | results.
        
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       (page generated 2022-01-09 23:01 UTC)