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Full listing of IMCL blog posts:


The sciences are revealing to us the power of networks - notably including urban networks. As Jane Jacobs, Christopher Alexander and others argued, we need to get this right.

EDITOR'S NOTE: This post is one in a series of discussion topics for the upcoming IMCL conference. Above is a 20-minute talk (click to view), and below is the transcript, by IMCL Executive Director Michael Mehaffy, given at the World Governments Summit on February 13th of this year.

So… I have some good news and some bad news, as the old saying goes!

The bad news is that in this year, 2024, we humans are far from anything like sustainable development. I think you all know what the challenges are – and they are profound. Our 150 year project of industrial modernity is in deep trouble, and it’s clear that profound changes must happen, and will happen – on our terms, or on disagreeable terms forced upon us. So we need to act.

The good news is that we are now able to see, for perhaps the first time in human history, what we must actually do to navigate the daunting transition ahead. We can see it because we now have the scientific understanding of the true nature of our challenges, and the tools we must deploy to meet them.

We are indeed on the frontier of a new industrial revolution – but a revolution that will redefine the very definition of industry, and the very definition of technology.

It will certainly be transformed by artificial intelligence – but even more profoundly, by what artificial intelligence reveals to us about natural intelligence, and the structure of nature – and human nature… and the nature of cities. And that’s what I want to explore with you today.

My own focus is on cities, and the role they play in creating both our challenges and our opportunities. After all, it’s in cities that we move about, interact, create, consume resources, and generate most of our ultimate impacts upon planet Earth. So we need to get this right.

And yes, some of that will involve adding new technologies, since we have always been a technological species. But more deeply, we will need to change our understanding of what cities are, and what they must become.

Let me explain what I mean with the example of the Webb Space Telescope, an astonishing technological feat, deployed flawlessly a million miles from Earth. And it's given us profound new insights into the nature of the Universe.

The Webb Space Telescope, an astonishing accomplishment of human technology, and human exploration.

And by the way, there are now two of these! The European Space Agency also has deployed the Euclid Space Telescope, in the same region of space.

Using similar technology, we may need to deploy solar shields to reduce solar heating, and protect the biosphere from the worst ravages of climate change.

But adding ever more technology to failing technology won’t help us, if we don’t address the deeper nature of the challenge.

More deeply, we will need to understand and exploit the technologies of living systems, the ways they can generate astonishing diversity, beauty, resilience and sustainability. These are the revolutionary new insights coming from the sciences.

And those living systems includes the living system of the brain, and the way it creates deep networks of knowledge and awareness. Neuroscientists call this the "connectome," and it gives us the picture of the world that we see -- not perfect, but useful -- and it provides our intelligence, and even our consciousness. This structure gives us our ability to tell, or to pick out, what is going on in the world. This is the secret of human intelligence. And it’s the secret of artificial intelligence too, the structure known as a neural network.

As you all know, there’s a lot excitement about AI, and considerable worry too, about how this technology will be used – or how it might use US! But there are two key points about AI: First, that it has the ability to assemble vast hyperlinked web-networks of data, or knowledge. And second, it has the ability to evolve and grow more intelligent over time – by itself, the way a child does. This is known as self-organization, and it’s a fundamental property of biological systems.

So the knowledge, or the data, is inter-connected into these vast clusters of web-networks. And they get more and more deeply interconnected over time, with ever more connections, forming “deep networks,” or we could say, “Deep Nets” for short.

We could contrast those with what we might call “Shallow Nets” – with few deep connections, maybe because they’re too new, or they have other problems. I’ll come back to that important point.

Now here’s an amazing thing: the natural world is full of these “deep nets,” from genetic codes, to the structures of proteins, to ecosystems, and much else.

And human language also has this deep-net structure, as we can see in a beautiful piece of poetry. Or in the linguistic knowledge represented, say, by an encyclopedia, with many deep connections between the different topics.

And as we saw, the brain itself has this deep-net structure, in the way it creates deep networks of knowledge and awareness.

And here’s another amazing and wonderful thing: Cities also have this deep-net structure. The spaces of a city also form a very complex adaptive web-network – a “deep net” – at large and small scales. Cities also learn, in effect, and incorporate intelligence, about how to make a successful and desirable place to live.

This idea may seem a bit abstract, so let me give you a concrete example. Below is a montage of a fairly ordinary London street, around the corner from where I used to live as it happens. And you can see many private rooms, but also more public room-like spaces, the little spaces created by terraces or balconies or the sidewalk frontages of buildings. And these room-like spaces are connected to each other in some ways, and often NOT connected in other ways. We can see but not hear through the glass, or hear but not see through the hedge, and so on.

A section of a street in London, UK.

And everything is connected to the street and to the public realm. It’s a remarkably deep web-network of connections, even for this one small section of one street.

And this “place network” is evolving and self-organizing over time, as people make small adaptations to control their desired level of contact and privacy. They close windows, open doors, and over longer spans of time, make major remodels or new buildings entirely.

They make bigger changes over longer times, as I found when I went back to this spot five years later.

There were new businesses and new paint colors, but also, new kinds of spaces, terraces above, a new stoop in front of the door below, and so on.

The same thing happens at even larger scales over longer spans of time, as we can see in the example of Venice over about a century.

Below is a drawing by the Italian architect and morphologist Muratori, and we can see the remarkable transformation and articulation of spaces and their connections… Right down to the ornamental details, developing into the city we all know and love today.

Above: drawing by Saviero Muratori (1959).

A similar bottom-up transformation happens in the natural world, where termites and other insects lay down chemical signals that they then use to build up highly sophisticated structures that control the temperature of their nests. It’s a phenomenon known as “stigmergy,” and it’s not controlled by a central authority – it’s a process of self-organization.

We humans do something similar – we lay down information in our environments, that then shapes further activities and emergent patterns of urban life.

And as the neuroscientists are finding, beauty is also an important form of information – telling us this is a good place, we will be well here, we can thrive here. And perhaps we will care more for that beautiful home, and sustain it for longer.

So, I suspect you can see now that, like brains, cities too can embody a deep form of intelligence, a “deep net” structure – and they can evolve and “learn” to be smarter, about how to provide a place where people can thrive.

Now this new understanding of how cities really work is still not well embedded into our “modern” systems. The remarkable journalist Jane Jacobs gave an early account in the early 1960s, when she described the “organized complexity” of cities.

Around that same time, the architect and theorist Christopher Alexander also pointed out that “a city is not a tree” – not a simple tree-shaped hierarchy, but rather, an interconnected “deep net”.

Alexander’s insight formed the basis of his “pattern language” methodology, which turned out to have surprising usefulness, of all things, in the field of software. And it led to surprising innovations in game design, wiki and Wikipedia, Agile methodology, and many more innovations.

Now you may remember the deep-net structure of encyclopedias that I described earlier, like Wikipedia. So it’s not a coincidence that many AI systems use Wikipedia, and other similar large language datasets, to generate very useful accounts of the world. They all exploit this deep-net structure.

It seems there’s a similar deep-net structure in the way economic expansion occurs in cities, as so-called “knowledge spillovers” connect diverse people within the public realm. Jane Jacobs wrote about this in detail, suggesting it was key to the powerful so-called “agglomeration benefits” of cities.

And this deep-net structure also seems to be the key to the surprising resource efficiencies of cities, especially more compact ones – they work not unlike ecologies, to maximize outputs while reducing and even regenerating resources.

This was a crucial point that Jane Jacobs made, near the end of her life, when she spoke of the coming “age of human capital” – expanding human development, while reducing and renewing natural resources. That is surely a key feature of the coming transition, and a goal of great importance.

So where does this leave us in thinking about the cities of the future?

For one thing, I think it tells us to be very skeptical of mechanical, fantasy-based images of yesterday’s future, that have their roots in the high consumption patterns of the early 20th century, well before our more recent scientific understanding of the deeply interconnected structure of nature, and human nature.

These approaches have not lived up to the fantasies – in fact, they have left us with a legacy that is, in a word, unsustainable.

For another thing, I think the sciences now reveal to us the formerly hidden collective intelligence embodied in the great cities and buildings of the past. It is not the images of these places that we must somehow imitate today. Rather, they embody deep knowledge, deep patterns — “deep nets” — for us to regenerate anew, as a kind of “DNA of place.”

I think this knowledge is very helpful in other ways too. We can now see the danger of what I earlier called “shallow nets” that we might say are “clogging up” the world. They’re producing very damaging outcomes and dysfunctions, in areas as diverse and seemingly unrelated as destructive social media, fake news, and political divisiveness… but also shallow image-based consumerism, the decline of critical institutions, market failures, choking bureaucracy… and unsustainable “externality costs,” as the economists refer to them. All of these trends imperil our civilization, and our future as a species.

I think we can also see it in the specific dysfunctions of urban settlements – for example, the social isolation and health impacts that come from sprawling, disconnected and over-encapsulated urban forms.

We cannot sustain the soaring externality costs that must be devoted to reconnecting people through automobiles and other machinery. And yet these are still dominant models of urbanization even today.

That is one reason why the United Nations’ Sustainable Development Goals, and their cousin, the New Urban Agenda, are so focused on this topic of sustainable urbanism. It is now urgent that we reform our failing paradigm of contemporary urban development, toward something less wasteful, more sustainable, more life-supporting – and by the way, actually more livable and more enjoyable!

Yet there is the uneasy sense today that the world is getting uglier… But perhaps that doesn’t matter, if we can just address the functional problems? Unfortunately, that view is not consistent with new research from neuroscience and other fields, which suggests that our experience of beauty or ugliness is intimately related to our need to find environments that are healthy and supportive of our own health and well-being.

We’re learning that these environments often exhibit forms of mathematical symmetry, not only bilateral but rotational, translational, scaling, and compound forms of symmetry. As Christopher Alexander showed, these symmetries emerge from the natural processes of healthy living growth, including the growth of cities. And when the growth of cities turns malignant, we naturally experience these place as ugly. When we are unable to experience a pleasing symmetry in our environments, evidence suggests that we may suffer a kind of “symmetry deficit disorder.”

So these and other new scientific insights offer us some very helpful new tools and strategies to reform our mistakes, and to transform our cities and towns into more flourishing, beautiful, sustainable and just places, ready to play their role in the great transition ahead.

The new tools include new and better kinds of urban codes, more supportive of informality and healthy growth. They include new economic mechanisms that can better value the growth of human capital, while also valuing the reduction of “externality costs,” including the depletion and emissions of our critical resources. There are promising new models, like the “15-minute city,” “isobenefit urbanism,” and what is called the New Urbanism.

The new tools also incorporate new expressions of the timeless knowledge of great human places and placemaking around the world and through history. We now see that these places embody rich complexities that we are only now beginning to understand and learn from, thanks to the profound new insights from mathematics and the sciences. These structures are ancient, to be sure — but they are also at the cutting edge of modernity and its challenges. And so too is our new understanding of them.

And by the way, below is an image of an entirely new settlement generated on those ancient patterns by ChatGPT 4!

So there is much more to do to develop and apply these lessons, through research and dissemination of practical lessons. That is one key goal of the new Rêve Institute, a center at the new Sorbonne Dubai.

I talked earlier about the deep-net structure of poetry, so let’s close with this thought-provoking passage from T.S. Eliot. Perhaps when it comes to the cities of the future:

We shall not cease from exploration

And the end of all our exploring

Will be to arrive where we started

And know the place for the first time.


The little-known concept of subsidiarity may actually address the core of our urban challenges. Here's why.

EDITOR'S NOTE: This post is part of a series on topics we will discuss at the 60th IMCL conference, "Making Cities Livable: Research Into Communication, and ACTION," April 26-28 in Newport, RI ( We hope you'll join us!

NEWPORT - Among the many challenges for our cities, towns and suburbs – perhaps at their very heart – is the growing problem of governance. Too often, “NIMBY” debates divide old allies, and paralyze needed reforms. Private interests “race to the bottom,” navigating byzantine and expensive regulatory processes that satisfy no one. Old destructive ways of doing things are perpetuated by “lock-in” – institutional and professional inertia, and worse, just plain turf protection.

A feature that is common to all these problems is that decisions are being made by people who are not best placed to make them. In some cases, the decisions are too “top-down” – by authorities with more interest in sustaining their institutional prerogatives than understanding and adapting to real local conditions and needs. In other cases, the decisions are too “bottom-up” – the rule of the mob, or the self-selected loudest voices with the greatest self-interests.

This is not a new kind of problem – nor is the potential solution new. In the governance world, the optimum balance between these two extremes is achieved by a principle known as “subsidiarity” – an idea that has been embraced by institutions as diverse as the Catholic Church, the United Nations, and the Congress for the New Urbanism. (1)

Jane Jacobs, in her landmark The Death and Life of Great American Cities, also focused on this concept (though not by name) in her chapter on “Governing Districts.” As she noted,

Here is an interesting thing about coordination both of information and of action in cities, and it is the crux of the matter: The principal coordination needed comes down to coordination among different services within localized places. This is at once the most difficult kind of coordination, and the most necessary… The invention required is not a device for coordination at the generalized top, but rather an invention to make coordination possible where the need is most acute—in specific and unique localities.

The solution, she said was to organize a series of governing districts of smaller size, appropriate to the needs of neighborhoods and their districts.

A similar concept has been implemented in Portland, Oregon, that city’s neighborhood and district association system – but that system was never a truly empowered subsidiary institution. Rather sadly and predictably, the system has become little more than a support group for angry, frustrated citizens. (And yes, sometimes they are obstructionist citizens – for they have power to do little else.)

Importantly, the principle of subsidiarity does not mean that larger scales “delegate power” to smaller ones. Rather, it is the reverse: the larger scales are subsidiary unions of the smaller ones. The United States is a subsidiary union of the people, and of their states.

But this is no "States’ Rights" doctrine. For the power to act on constitutional issues has already been vested irrevocably by the people and their states in the federal government and its courts – not the states. Crucially, the power to act derives upwardly from “the consent of the governed” – but it is a consent not to weigh in on any and every decision, but to enter into a binding commitment to a union, or a series of overlapping unions, with appropriate governance and representation structures – in this case, structures of subsidiary, “polycentric” (and far from autonomous) institutions.

The idea of “polycentric” governance is not unlike “polycentric urbanism:” there are many centers with many overlaps. The concept was promoted most memorably by Nobel Prize-winning political economist Elinor Ostrom. The governance is not only formal govern-ment, but informal gover-nance institutions too -- including civil society, the professions, universities, neighborhood businesses, and even families. We are in big trouble when those institutions are eroded -- as Jacobs warned we are indeed, in her last, disquieting book, Dark Age Ahead.

Refreshingly, the principle of subsidiarity, and the pragmatic local action it advocates, is not a “left” or “right” ideological issue. In fact, many people of very different ideologies can come to agreement and practical collaboration when it comes to the quality and livability of their own neighborhoods – a hopeful observation in a time of divisive politics. I myself, like many who work with local jurisdictions, have witnessed this collaborative unity. It does require a healthy framework of subsidiary governance, and a willingness to overcome barriers, to find a path to optimum “win-wins”.

One of the big problems of our time is surely the breakdown of this balance of subsidiarity, in favor of large disempowering bureaucracies, whether public or private. The history of the 20th century (well into our 21st) has been a history of institutional gigantism, and that has played out in cities too. This is the “too big to fail” syndrome -- and as we saw in 2008, it carries enormous dangers for the stability of the institutions on which we all depend. This is not to mention the routine degradations of local quality of life, planetary health, and the creaking unsustainability of our critical systems.

This dynamic is surely a major driver of the rise of populism in the US and internationally, as anger and frustration grow at the sense of disempowerment and disrespect of local perspectives, prerogatives and needs. It then becomes too tempting to blame scapegoats, to be swayed by demagogues, and not to identify the bigger and more intractable problem (and the nonpartisan one) -- that of balanced, healthy governance scale.

Into this vacuum, between the gigantism of institutions and the gridlock of an understandable if misdirected populism, come rushing the expert private interests who know how to game the system. In particular, they know how to exploit the financialization of everything in sight, and to expertly squeeze out every drop of value for themselves and their shareholders. It is not surprising, then, that real estate values are soaring, along with displacement, gentrification, homelessness, desperation, and a host of other social ills.

It is also not surprising that the quality of our built environment continues to erode, as we calibrate the price of everything, and the value of nothing. We measure and value every square inch of “heated and cooled space,” while essential outdoor spaces, and the essential transition structures that frame them, are discounted, and then (of course) stripped bare. We measure the “functionalism” of a “modernist” building, stripping away all the decorative delights that serve as essential “connective tissue” to the urban and pedestrian realm – and then we are surprised that cheap suburban tract houses crudely copy our minimalist tricks, with dispiritingly shoddy results. (And yet they still soar in price, as the experts expertly financialize every square inch.) We measure the economic throughput of automobiles, miles of roadway, and miles of unwalkable suburbia -- but not the soaring “externality costs” of air pollution, social isolation, and other impacts on human and planetary health.

This is an unsustainable situation, in every sense of the word.

Addressing it will require, firstly, a recognition of the problem of governance and scale, embodied in the principle of subsidiarity. That will surely take the form of better local governance (e.g. neighborhood quality of life issues, vandalism, safety, and other basics of good governance), as well as reforms to obsolete and exclusionary zoning codes, and better forms of funding for housing and affordability. These are tangible and pragmatic first steps (and the “day jobs” for myself and many others who work with municipalities in this area).

More broadly, this situation may require a re-conception of the mechanisms of valuation for different forms of capital, understanding that land and natural resources are fundamentally different – and fundamentally more limited in supply – than forms of human capital and cultural wealth. This idea was expressed most famously by the 19th Century American economist Henry George, whose work was once celebrated across the political spectrum. This idea has since taken root as a “land value tax,” a “carbon tax,” and related economic concepts aimed at “valuing externalities,” or public goods and costs that are outside of (that is, "external" to) normal transaction pricing.

This idea was also one that Jane Jacobs was known to be working on toward the end of her life, in a book she had provisionally titled “the Age of Human Capital.” In contrast to her previous work, Dark Age Ahead – raising a necessary alarm about the challenges we faced from the breakdown of critical human institutions – the new book was to focus on a much more hopeful future. We do have choices, she would suggest – and perhaps even, the choice of a new golden age for human settlements. But meanwhile, there is much work to do.

(1) The New Urban Agenda, the outcome document of the 2015 Habitat III conference, was adopted by acclamation by all 193 countries of the United Nations, and among its provisions is the following: “We will develop and implement housing policies at all levels, incorporating participatory planning and applying the principle of subsidiarity, as appropriate, in order to ensure coherence among national, subnational and local development strategies, land policies and housing supply” (Para. 105). I am also indebted to Andrés Duany, co-founder of the Congress for the New Urbanism, who has promoted the concept of subsidiarity as it relates to urbanism.


Topics will include coastal flooding, beach erosion, public space access, resilience, climate-friendly planning, housing affordability, zoning reform, walkability and transportation reform, and more; plans are under way for tours on Friday the 26th and Monday the 29th

A postcard of a Newport beach from the 1930s.

NEWPORT, RI USA - The early bird registration rate ends today for the 60th International Making Cities Livable (IMCL) conference set to occur in this beautiful coastal town, April 26-28, 2024.

Like many coastal cities around the world, Newport is facing severe challenges from flooding, beach erosion and related challenges. The city is also experiencing many other familiar challenges for cities around the world, including housing unaffordability, lack of suitable "middle" housing, lack of walkability and recreational opportunities, uneven distribution of high-nutrition food sources (AKA "food deserts") and similar challenges, The IMCL conference will examine Newport's challenges with the Rhode Island Department of Health and other partners, as well as the challenges and opportunities of other cities.

The conference title is "Making Cities Livable: Research Into Communication, and ACTION." During the intensive, intimate symposium, leading researchers will join policymakers, practitioners, and NGO heads to assess the latest research and case study lessons, considering both new and existing neighborhoods, cities and towns. Accepted and invited speakers come from every continent except Antarctica.

Our venue is the beautiful Bois Doré estate, made available through the generous sponsorship of Fairfax and Sammons Architects. The building is very close to the Newport's walkable downtown, and to a number of hotels, inns, and B&Bs. It includes a main plenary space and a number of spaces for breakout sessions and meetings.

Newport is readily accessible by train from New York, Boston and Providence, via the Amtrak station in Kingston (a short distance away by bus, taxi or Uber). Bus connections are also available in Providence and other cities.

Case studies will assess successes and lessons learned, with a focus on practical and effective actions. We will explore the latest research and its application to current challenges, as well as ongoing collaborations to facilitate additional research and development of new tools and strategies among the partners.

In addition to the Rhode Island Department of Health, local partners will include Bike Newport, Roger Williams University, and others to be announced shortly. They will join senior representatives of The King's Foundation (UK), the Congress for the New Urbanism, the International Network for Traditional Building, Architecture, and Urbanism (INTBAU), UN-Habitat, HealthBridge Canada, The Seaside Institute, PlacemakingX, The Urban Guild, and others to be announced.

Participants will have the opportunity to participate in tours of landmarks and case studies in Newport and Providence. The tours will occur on Friday prior to the opening reception, on Monday after the conference, and possibly in some cases, during the conference itself. More information will be announced soon.

Please join us! More information is at

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