I spent a year traveling to communities all over the country looking for the answer to this question.
I think the answer has to depend on why the community exists; there are different types of communities based on different shared goals. These can each be healthy or unhealthy in different ways based on how those goals are pursued and the kind of governance that happens.
Slab City is a place that people can go, no matter what. As a place that people can go no matter what, it is not trying to be a place where people can thrive or where people have great healthcare or jobs. So healthy there means anything that lets people come there no matter what. It’s complete anarchy and there is zero governance, and people actively, violently resist any kind of governance. There are community fortresses built to isolate parts of town like mad max, where smaller groups try to establish governance and thrive together to some degree, but the shared consensus among the broader community is very different from these isolated pockets.
There’s a secret food forest commune in rural south central Tennessee that is a place where people grow food without any technology allowed on the site. As a place where people grow food without any technology allowed on the site, a whole different set of things becomes important, and the way that plays out can be healthy or unhealthy depending on how the shared consensus around the objectives evolves over time. They build tree houses a hundred feet in the air and abandon the land during the flood season, returning afterwards to their ewok-like community in the trees.
There’s an arcology in rural Arizona where around a hundred people live and work, mostly for free, on popularizing the idea of arcologies. For them, being healthy means having enough food and water and finding ways to cool off in the summer, plus working towards shared goals around popularizing the concepts around arcology. Most of them live without healthcare or a living wage, and just work until they burn out, then leave.
Then there are a lot of places like The Federation of Egalitarian Communities, Crestone, Oneida, Taos, Santa Fe, Basalt, or my hometown of Ashland where people are (or have in the past been) really trying to build vibrant and thriving communities based on radically sustainable alternative ways of building homes and building inclusive and accessible communities that will allow people to survive and thrive through what’s coming in the next few years and decades.
One of my favorite communities I’ve visited is The Garden in Tennessee which has an open door policy, and lets anyone come see the community and experience what being at a sustainable off-grid community is like. They specialize in helping people find a forever-home in one of many similar sustainable off-grid community (that typically don’t have the same open-door policy).
In short, there is no real answer to the question, or there are at least as many answers to this question as there are examples of communities, or perhaps there are at least as many answers as there are people at these communities. Personally, I think of the health of a community as how clear the shared consensus is on what they are doing together and why, and on how responsive the governance structure is to the concerns of the members, and especially on how diversely inclusive the community is; across not just race, ethnicity, and gender but also on factors like ability and economic accessibility.
What makes a community unhealthy?
It’s easier to talk about the things that make a community unhealthy; typically exploitation by the governance structure or the “owners.” It’s very common for greedy people to pretend their business is a community in order to attract people who lack community and get them to give uncompensated labor. It’s very common for social groups related to causes or identities to “identify” as a community or as a substitute for missing friends and family in people’s lives. Both of these examples play out constantly, and you see it whenever a group of tech bros who have never lived in a community decide to “start a commune” or pool resources to buy a farm to share, with no idea of how to run a farm or share power and space with other people.
I think a lot of people have this naive intuition that building or living in a community is easy or natural; and without any actual experience of doing either thing, they stumble through trying until they burn out and return to some cubicle somewhere to live out their lives under fluorescent lights as a discontented libertarian; this story plays on repeat all day in San Francisco.
I think spending time at lots of communities is a good first step to being able to answer the question for yourself; developing a long list of things that work and things that don’t work and how conflicts are resolved and the pros and cons of different governance structures. The second step is deciding what you would want in a community. The third step is doing the hours and days and weeks of work of actually talking through all of that and developing a shared consensus with a group until you can all agree on enough of these things to actually function together as a unit. Then laying it all out in writing together and agreeing on how governance and ownership and power are shared and how they are defined and what you are doing together and why you are doing it. Only then does it become possible to build a healthy community.
Then it becomes about building a system of permaculture and mutual aid together so that those community bonds strengthen over time as you work together on the shared project of doing all the things you agreed on and feeding yourselves and sheltering yourselves and helping each other fulfil your shared vision.