Growing Up with Urban Externalities
When we organized the UC Berkeley Mexico Development Lab’s visit to Mexico City, some of my Indian colleagues surprised me by saying how “at home” they felt in the metropolis. Their reaction stayed with me. I wondered what could make a city feel familiar to people who had grown up so far away.
It brought me back to my own childhood in Guadalajara, where navigating the city meant learning an unwritten set of rules alongside the official ones. A traffic signal told you when you could cross. Experience taught you to look again.
Growing up, life often felt like a cacophony of disarray. I learned to anticipate risk: scanning the bus for signs of trouble, wondering whether someone might be waiting near the train tracks, and calculating when I could cross a wide avenue without stepping into the path of a speeding car. Whatever protection traffic laws promised, crossing the street often came down to reading the intentions of a driver inside a one- or two-ton moving object—and trusting my own vigilance.
There is a particular kind of education in that experience. You learn to read a street as others might read the weather: watching for small changes, judging what might happen next, deciding whether to move or wait. That knowledge can make you resourceful. It also asks something of you every time you leave home.
The price of an unsafe crossing includes the attention you must give it, even on a day when nothing happens.
That vigilance extended beyond traffic. I remember homeowners sweeping their sidewalks and rubbish collecting around drains. During the rainy season, plastic bags, bottles, and rags could become obstacles to an entire street’s drainage. Water moving downhill carried the consequences of what had accumulated upstream.
Drinking water carried its own uncertainty. The expectation around me was that water needed treatment before we could trust it. Something as ordinary as having a glass of water required an additional decision: where it came from, how it had been treated, whether it was safe.
These experiences taught me something long before I had the economic vocabulary for it: when public systems fail, someone still pays.
Sometimes that payment is visible—money spent on drinking water, repairs, or a safer way to get somewhere. Sometimes it is time spent waiting, taking a longer route, or arranging a private substitute for an unreliable service. Sometimes it is the mental effort of remaining alert.
A household becomes the last line of defense, patching gaps it did not create. Those with enough money can build a thicker layer of protection around themselves. Others must absorb more of the inconvenience, exposure, and risk. Resourcefulness helps people get through the day, but it should not become an excuse for expecting them to compensate indefinitely for systems that do not serve them.
The city I experienced seemed to make more room for cars than for the people walking beside them. A wide avenue could move vehicles efficiently while making a short walk difficult or dangerous. The apparent success of the road depended on where you stood: behind a windshield, or at the curb trying to cross.
Taking the bus meant adapting to conditions over which passengers had little control. What stayed with me was the feeling that your safety and comfort depended heavily on whether you could afford another option. The ability to leave a public problem behind—to get into a car, take another route, pay for an alternative—is itself a form of privilege.
This is where city design becomes a question of externalities: costs or benefits that a decision creates for people outside that decision.
A driver gains a little time by speeding, while a pedestrian bears additional risk. Rubbish discarded in one place can obstruct drainage and contribute to problems elsewhere. The convenience belongs to one person; part of the bill arrives at someone else’s door.
Not every failure of public services is an externality. Some are questions of unequal access, inadequate investment, or poor administration. But these problems meet in the same streets. Together, they determine whose convenience receives protection and whose difficulties become an ordinary, almost invisible part of city life.
Calling them externalities gives us a way to examine how those costs travel. It should also make us question the word “external.” The cost may sit outside a driver’s calculation or an organization’s accounts. It remains firmly inside somebody else’s life.
I grew increasingly frustrated by the distance between visible public projects and the less glamorous work of making a city function. A monument is easy to inaugurate and photograph. A drain that works through the rainy season attracts less attention. Yet maintenance, safe crossings, dependable transit, and clean water are the infrastructure through which people experience government most directly.
That comparison needs care. Parks, plazas, and monuments can enrich a city; public beauty matters too. What troubles me is the temptation to judge a project by its visibility while neglecting the care that allows people to use the city safely. A beautiful plaza and a functioning drain should belong to the same understanding of public responsibility.
The same question of accountability applies to businesses. When enforcement is uneven, a firm that pays for safety measures or environmental compliance can face costs that a competitor evades. If evasion brings an advantage, responsible conduct becomes harder to sustain.
The unpaid costs still go somewhere: to workers exposed to danger, neighbors living with pollution, or public services dealing with the consequences. Weak enforcement allows those costs to move beyond the organization’s boundary, where they become harder to trace back to the decisions that produced them.
I understand why people turn toward private solutions when collective ones disappoint them. Waiting for institutions to improve does not get you safely across a road today. But a city cannot depend on every household purchasing its own escape route. The people with the fewest alternatives remain most exposed, while those able to leave the problem behind may encounter less of it in their daily lives.
My childhood memories cannot describe every neighborhood in Guadalajara, much less every city in Mexico. They are memories of particular places and experiences, shaped by where I stood and how I moved through them. They explain why I have difficulty treating urban policy as something abstract.
I encounter it in the memory of a street I hesitated to cross, a bus ride that required alertness, or rainwater carrying rubbish downhill. What later became questions of incentives, regulation, and public investment first reached me as questions of how to get home.
Real change requires institutions people can depend on: maintenance that happens before a flood, crossings designed around human vulnerability, transparent public spending, and service standards that residents can hold someone accountable for meeting.
Participation matters, too. Residents know where water collects and which crossing feels dangerous. Their knowledge should inform decisions, and they should be able to see what happens after they report a problem. But participation becomes exhausting when it means repeatedly asking for basic services or supervising work that an institution is already responsible for doing. Citizens need a meaningful voice without having to become full-time monitors of the systems meant to serve them.
I want cities where walking, taking the bus, breathing clean air, and drinking safe water do not require private substitutes or constant vigilance. Cities where working-class people can move with dignity, and where public space offers room for expression, encounter, and opportunity.
I would measure progress partly by how much vigilance a city allows its residents to put down. Can a child cross with confidence? Can a passenger trust the journey? Can a household rely on the water and drainage systems around it?
The city I want would give people more room to direct their attention toward living, instead of continually calculating how to protect themselves.
Who pays for the city—and who gets to feel protected within it—should be central to how we build and govern it.
