Communities are not fungible

There’s a default assumption baked into how Silicon Valley builds products, and it tracks against how urban planners redesign neighbourhoods: that communities are interchangeable, and if you “lose” one, you can manufacture a replacement; that the value of a group of people who share space and history can be captured in a metric and deployed at scale.

Economists have a word for assets that can be swapped one-for-one without loss of value: fungible. A dollar is fungible. A barrel of West Texas Intermediate crude is fungible.

…A mass of people bound together by years of shared context, inside jokes and collective memory is not.

And yet we keep treating communities as though they are.

When a platform migrates its user base to a new architecture, the implicit promise is that the community will survive the move. When a city demolishes a public housing block and offers residents vouchers for market-rate apartments across town, the implicit promise is that they’ll rebuild what they had.

These promises are always broken, and the people making them either don’t understand why, or they’re relying on the rest of us being too blind to see it.

What Robert Moses got wrong…

Robert Moses displaced an estimated 250,000 people over the course of his career, razing entire neighbourhoods to make way for expressways and public works projects. The defence of Moses, then and now, is utilitarian: more people benefited from the infrastructure than were harmed by its construction. The calculus assumed that the displaced residents could form equivalent communities elsewhere, and the relationships severed by a highway cutting through a block were replaceable with relationships formed in a new location. Jane Jacobs spent much of her career arguing that this was catastrophically wrong. The old neighbourhood was not a collection of individuals who happened to live near each other; it was a living organism with its own immune system and its own way of metabolising change. When Moses bulldozed it, he killed a community and scattered the remains.

Jacobs understood that the value of a community isn’t in the people as discrete units. The value is in the specific, unreproducible web of relationships between them. You can move every single resident of a street to the same new street in the same new suburb and you will not get the same community, because community is a function of time and ten thousand microtransactions of reciprocity that nobody tracks and nobody can mandate.

…and what economists miss

In a model, agents are interchangeable. Consumer A and Consumer B have different preference curves, yes, but they respond to the same incentive structures in predictable ways. Community is what you get when agents stop being interchangeable to each other. When Alice doesn’t need “a neighbour” but needs that neighbour, the one who watched her kids that time, the one who knows she’s allergic to peanuts. The relationship is specific, and specificity is the enemy of fungibility.

This is why so many attempts to “build community” from scratch end up producing something that looks like community but functions like a mailing list. The startup that launches a Discord server and calls it a community // the coworking space that holds a monthly mixer and calls it a community etc. What they’ve actually built is a directory of loosely affiliated strangers who share a single contextual overlap.

That’s a starting condition for community, but it’s not community itself, and the difference is like the difference between a pile of lumber and a house. The raw materials are necessary but wildly insufficient.

When platforms die, communities don’t migrate

The internet has run this experiment dozens of times now, and the results are consistent. When a platform dies or degrades, its community does not simply migrate to the next platform, it fragments, and the ones who do arrive at the new place find that the social dynamics are different, the norms have shifted, and a substantial number of the people who made the old place feel like home are gone. LiveJournal’s Russian acquisition scattered its English-speaking community across Dreamwidth and eventually Twitter. Each successor captured a fraction of the original user base and none of them captured the culture. The community that existed on LiveJournal in 2006 is extinct and cannot be reassembled. The specific conditions that created it, a particular moment in internet history when blogging was new and social media hadn’t yet been colonised by algorithmic feeds and engagement optimisation, no longer exist.

You can see the pattern in Vine’s death and the migration to Snapchat x TikTok, with Twitter’s degradation and the scattering to Threads, Bluesky and Mastodon. In every case, the platform’s architects // successors assumed that the product was the platform and the community was an emergent feature that would re-emerge given similar conditions. They had the relationship exactly backwards. The community was the product and the platform was the container, and when the container breaks, the product spills and evaporates, and some of it is lost forever.

Dunbar’s layers + the archaeology of trust

Robin Dunbar’s research on social group sizes tells us that humans maintain relationships in rough layers: about five intimate relationships, fifteen close ones, fifty good friends, and a hundred and fifty meaningful acquaintances. These aren’t arbitrary numbers; they mirror cognitive and emotional bandwidth constraints that are probably neurological in origin. What Dunbar’s model implies about community is underappreciated. If a community is a network of overlapping Dunbar layers, then each member’s experience of the community is unique, shaped by where they sit in the web. There is no “the community” in any objective sense. There are as many communities as there are members, each one a different cross-section of the same social graph, and this means that when you lose members, you lose entire subjective communites that existed literally nowhere else.

When a Roman town was abandoned, the physical structures decayed at different rates. Stone walls lasted centuries while textiles vanished in years. The social structure of a community decays the same way when it’s disrupted. The institutional relationships, the stone walls, might survive: people will still know each other’s names and professional roles. The close friendships might last a while, held together by active effort. But the ambient trust, the willingness to lend a tool without being asked or to tolerate a minor annoyance because you’ve built up enough goodwill to absorb it, that’s the textile, and it goes first. Once it’s gone, what’s left = a skeleton that looks like a community but has lost the capacity to function like one.

Why “build a new one” doesn’t work

There’s a fantasy popular among technologists and policymakers that community can be engineered. That if you identify the right variables and apply the right interventions, you can produce community on demand. This fantasy has a name in the urbanist literature: it’s called “new town syndrome,” after the observation that Britain’s postwar new towns, carefully designed with all the amenities a community could need, produced widespread anomie and social isolation in their early decades. Stevenage had shops, schools, parks and pubs. What it didn’t have was history. The residents had no shared past and no slowly accumulated social capital. They had proximity without context, and proximity without context is a crowd.

The same problem pops up in every domain where someone tries to instantiate community from a blueprint. Corporate culture initiatives and neighbourhood revitalisation programs tend to optimise for the visible markers of community, events and shared spaces, while ignoring the invisible substrate that makes those markers meaningful. It’s like building an elaborate birdhouse and assuming birds will come, and when they don’t, the birdhouse builders typically conclude that they need a better birdhouse, rather than questioning wether birdhouses are how you get birds.

You can’t rerun the history

The destruction of a community is largely irreversible. You can rebuild a building and you can replant a forest and, given enough decades, get something that resembles the original ecosystem. But a community that took twenty years to develop its particular structure of norms and mutual knowledge cannot be regrown in twenty years, because the conditions that shaped it no longer exist. The people are older, the context has changed, and the specific convergance of circumstances that brought those particular individuals together in that particular configuration at that particular time is gone. Communities are path-dependent in the strongest possible sense: their current state is a function of their entire history, and you can’t rerun the history.

Ursula K. Le Guin wrote in The Dispossessed about the tension between a society that valued radical freedom and the structures that emerged organically to make collective life possible. Her protagonist, Shevek, discovers that even in a society designed to prevent the accumulation of power, informal hierarchies and social obligations develop on their own, shaped by nothing more than time and proximity. Le Guin understood that community structure isn’t designed, it’s deposited, like sediment, by the slow accumulation of interactions that nobody planned and nobody controls.

So what do we actually owe existing communities?

If communities are non-fungible, if they can’t be replaced once destroyed, then every decision that disrupts an existing community carries a cost that is systematically undervalued. The cost doesn’t show up in a spreadsheet because it’s not a line item, it’s the loss of a particular, specific, irreproducible social configuration that provided its members with things that can’t be purchased on the open market: ambient trust and the comfort of being known.

Displacement – whether physical or digital – is more expensive than anyone budgets for. The burden of proof should fall on the displacer, not the displaced, to demonstrate that the benefits of disruption outweigh the destruction of social capital that took years or decades to accumulate. And the glib promise of “we’ll build something even better” should be treated with the same scepticism as a contractor who promises to replace your load-bearing wall with something decorative. It is, to be frank, bullshit.

Communities are not resources to be optimised and they’re not user bases to be migrated. They’re the accumulated residue of people choosing, over and over again, to remain in a relationship with each other under specific conditions that will never, ever recur in exactly the same way.

Treating them as fungible is idiotic, and we have been far too willing to let it happen unchallenged.