Monthly Archives: December 2010

A universal theory of cities

CC Image from lopolis

CC Image from lopolis

Last week, the New York Times Magazine featured a lengthy piece from Jonah Lehrer about two physicists who have formulated a sort of universal law for urban living.  The single biggest determinant of urban performance is size – increasingly large agglomerations offer economies of scale – people who live and work there are more productive, more creative, etc.  The physicists (Geoffrey West and Luis Bettencourt) summarize their main conclusions:

Three main characteristics vary systematically with population. One, the space required per capita shrinks, thanks to denser settlement and a more intense use of infrastructure. Two, the pace of all socioeconomic activity accelerates, leading to higher productivity. And three, economic and social activities diversify and become more interdependent, resulting in new forms of economic specialization and cultural expression.

We have recently shown that these general trends can be expressed as simple mathematical ‘laws’. For example, doubling the population of any city requires only about an 85% increase in infrastructure, whether that be total road surface, length of electrical cables, water pipes or number of petrol stations. This systematic 15% savings happens because, in general, creating and operating the same infrastructure at higher densities is more efficient, more economically viable, and often leads to higher-quality services and solutions that are impossible in smaller places.

These core economies of scale, positive feedback loops, and benefits of agglomeration are what lets cities be cities.  Now, we have some math behind it.

Some more quotes from the NYT Mag piece.

On urban systems:

There is something deeply strange about thinking of the metropolis in such abstract terms. We usually describe cities, after all, as local entities defined by geography and history. New Orleans isn’t a generic place of 336,644 people. It’s the bayou and Katrina and Cajun cuisine. New York isn’t just another city. It’s a former Dutch fur-trading settlement, the center of the finance industry and home to the Yankees. And yet, West insists, those facts are mere details, interesting anecdotes that don’t explain very much. The only way to really understand the city, West says, is to understand its deep structure, its defining patterns, which will show us whether a metropolis will flourish or fall apart. We can’t make our cities work better until we know how they work. And, West says, he knows how they work.

On similarities and dissimilarities to natural systems:

[T]he real purpose of cities, and the reason cities keep on growing, is their ability to create massive economies of scale, just as big animals do. After analyzing the first sets of city data — the physicists began with infrastructure and consumption statistics — they concluded that cities looked a lot like elephants. In city after city, the indicators of urban “metabolism,” like the number of gas stations or the total surface area of roads, showed that when a city doubles in size, it requires an increase in resources of only 85 percent.

What Bettencourt and West failed to appreciate, at least at first, was that the value of modern cities has little to do with energy efficiency. […] In essence, they arrive at the sensible conclusion that cities are valuable because they facilitate human interactions, as people crammed into a few square miles exchange ideas and start collaborations. “If you ask people why they move to the city, they always give the same reasons,” West says. “They’ve come to get a job or follow their friends or to be at the center of a scene. That’s why we pay the high rent. Cities are all about the people, not the infrastructure.”

On positive feedback loops:

West and Bettencourt refer to this phenomenon as “superlinear scaling,” which is a fancy way of describing the increased output of people living in big cities. When a superlinear equation is graphed, it looks like the start of a roller coaster, climbing into the sky. The steep slope emerges from the positive feedback loop of urban life — a growing city makes everyone in that city more productive, which encourages more people to move to the city, and so on. According to West, these superlinear patterns demonstrate why cities are one of the single most important inventions in human history. They are the idea, he says, that enabled our economic potential and unleashed our ingenuity. “When we started living in cities, we did something that had never happened before in the history of life,” West says. “We broke away from the equations of biology, all of which are sublinear. Every other creature gets slower as it gets bigger. That’s why the elephant plods along. But in cities, the opposite happens. As cities get bigger, everything starts accelerating. There is no equivalent for this in nature. It would be like finding an elephant that’s proportionally faster than a mouse.”

Scarcity is the check on this superlinear growth, and innovation is what breaks that check.

On counterpoints to these universal laws: Lehrer quotes suburbanist Joel Kotkin in his piece, with Kotkin arguing against this logic of density and economies of scale, citing Silicon Valley and the Research Triangle.  Kotkin is too focused on the traditional narrative of cities and suburbs, however.  Both of those examples are still agglomeration economies, just comprised in a different physical form. A ‘city’ here is also the total urban area, not the arbitrary political boundaries that Kotkin often hangs his hat on.

It’s also important to note that this kind of universal law sets the baseline for what’s to be expected of a city – certain places will under or over-perform.  That’s where the quality of a place comes in, in my estimation.

On qualitative measures: West and Bettencourt specifically avoid the qualitative, since they can’t measure it well with data.  It’s important to not set qualitative and quantitative measurements in opposition, however.  WNYC’s RadioLab delved into the qualitative aspects of what makes cities into cities back in October.  These different explanations of cities are not mutually exclusive.  Indeed, they are complimentary.

This discussion, both the qualitative and quantitative aspects of it, seem to further embrace the Three D’s of density, diversity, and design.  The question is then about how to assess each of those factors.  Given that each one of those factors can be defined expansively (diversity of people, of skills, of land use, of incomes, of languages, of cultures, etc) and not all of those varied elements can be effectively quantified, this only reinforces the co-dependence of both analytical methods.

On planning: Lehrer closes his piece with a note about the inherent messiness of cities – the “energized crowding”, to steal a phrase from Spiro Kostof.

Unlike companies, which are managed in a top-down fashion by a team of highly paid executives, cities are unruly places, largely immune to the desires of politicians and planners. “Think about how powerless a mayor is,” West says. “They can’t tell people where to live or what to do or who to talk to. Cities can’t be managed, and that’s what keeps them so vibrant. They’re just these insane masses of people, bumping into each other and maybe sharing an idea or two. It’s the freedom of the city that keeps it alive.”

One common misconception about planners and planning is that we seek to control everything.  Instead, I am more interested in this kind of messy interaction.  Planning is about facilitating those interactions, not about controlling them.  For that reason, I find this kind of research fascinating.

The entire piece is fantastic.  Read the whole thing.

Agglomeration, continued

Nike Agglomeration crop

More items of note on agglomeration:

From City Journal, the “Seven Pillars of Agglomeration.”

  1. Economies of scale in production
  2. Economies of scale in trade and transportation
  3. Falling transportation and communication costs
  4. Proximity with other firms in the same industry
  5. Advantages of diversity
  6. The quest for the center (of the industry)
  7. Buzz and bright lights

And, from The New Republic‘s Avenue blog, a visualization of those principles in action, looking at the athletic and outerwear industry in Portland, OR – from Pendleton (1889) to Nike (1978).

But the A&O cluster is also an interesting case study in cluster morphology and dynamics. Check out this cool genealogy map developed by sometime Metro Program author Heike Mayer of the University of Bern, for example. Meyer’s info-graphic shows well how the A&O cluster has grown over time and now epitomizes the frequent structure of highly dynamic clusters, which often find a small number of large foundation firms (in this case Nike, Adidas, and Columbia Sportswear) surrounded by a cloud of scores of smaller, more entrepreneurial firms. In Portland, hundreds of these small and sometimes tiny firms are now proliferating–driving growth, developing their own niches, and providing services to the bigs and larger new firms.

The accompanying infographic (full size image – PDF file) shows this phenomenon in action, and through time.  As noted, building on these existing clusters, taking advantage of these agglomerations is the smart approach to economic development:

All together, it’s a great example of how the best sort of economic development eschews chasing after firm relocations and other silver bullets and instead concentrates on “organic” growth that arises from local distinctiveness.

Agglomeration is about letting cities be cities.

Nightlife agglomerations & the corner bar

The Corner Bar, Divernon IL - CC image from Randy von Liski

The Corner Bar, Divernon IL - CC image from Randy von Liski

A few booze-related items I thought I’d comment on:

The Hill is Home takes note of ANC 6B‘s seemingly preferred method to avoid “Adams Morganization” – a moratorium on all new liquor licenses.  Nevermind that the trigger for this fear of Adams Morgan is Moby Dick House of Kebob – which makes me think those leveling this barb have neither visited Adams Morgan recently nor dined at Moby Dick.

Matt Yglesias notes that such efforts to control liquor licenses is fighting the natural tendencies urban economics, where things like to cluster.  That’s what cities are, after all – clusters and agglomerations of people, firms, skills, capital, etc.  Yglesias makes a great point about the appropriate scale of governance of these issues.  While small, local groups (such as an ANC) might be affected by a new bar or restaurant, the practice of giving them veto power over things like liquor licenses has some severe implications:

The bigger question here is about levels of governance. Insofar as you empower residents of my building in DC to make the decision, we will attempt to regulate the food service establishments on our block so as to minimize late-night noise. After all, the service sector jobs lost in the process aren’t the jobs that we do while as homeowners we bear the losses of reduced property values on the block. And to simply disempower us, as a block, would be arbitrary and unfair. But empowering each and every block leads to highly inefficient outcomes with the bulk of the pain felt by low-income people and there’s no obvious reason of justice to think this kind of hyper-local empowerment is more legitimate than taking a broader view would be.

Ryan Avent adds on, noting that these kinds of restrictions and inefficiencies lead to poor outcomes for consumers:

That’s largely because it’s very difficult to open new bars. And the result is a pernicious feedback loop. With too few bars around, most good bars are typically crowded. This crowdedness alienates neighbors, and it also has a selecting effect on the types of people who choose to go to bars — those interested in a loud, rowdy environment, who will often tend to be loud and rowdy. This alienates neighbors even more, leading to tighter restrictions still and exacerbating the problem.

Sadly, this is the kind of dynamic that’s very difficult to change. No city council will pass the let-one-thousand-bars-bloom act, and neighbors can legitimately complain of any individual liquor license approval that it may lead to some crowded, noisy nights. It’s interesting how often these multiple equilibrium situations turn up in urban economics. In general, they seem to cry out for institutional innovation.

Avent specifically laments DC’s lack of the ol’ neighborhood corner bar.  Having been born and raised in the boozy midwest, where the small, corner bar is an institution and people drink alcohol the way others drink water, I miss the corner bars, which aren’t as common as they could be in the District.

One of the problems is in the tools used to limit these licenses.  As Avent and Yglesias note, the kinds of tools bandied about by ANCs lead to an inefficient marketplace.  Instead of preventing Adams Morgan, something like a moratorium ends up ensuring a slippery slope towards “Adams Morganization” rather than preventing one.

On the broader issue of retail mix (ANC 6B’s stated reason to oppose new liquor licenses), the December issue of the Hill Rag had two contrasting pieces on the issue of retail on Barrack’s Row.  The first discusses potential options – none of which seem palatable for actually encouraging retail.  Regarding a moratorium, the impact is exactly what Avent describes:

One problem he cites is that it seems to be “too easy to become a bar or pub once you have the license.” So, even if there is a moratorium on new licenses, there is always the chance that existing licenses can morph from restaurants, which most neighborhoods don’t mind, to bars that operate later and attract different customers.

Another suggested tool is a zoning overlay district, but such a tool is a mismatch between the stated problem and solution.  Zoning is best used to regulate the physical form and the use of buildings, broadly defined.  Zoning can separate a retail use from a residential one, or an office use from light industry – but it is not an adept tool to parse out specific kinds of retail, or in differentiating between Moby Dick and Chateau Animeaux. The issue of bars and liquor licenses is more an issue of how those physical spaces are programmed.  Zoning is not a good tool to control these kinds of issues, and these types of regulations often backfire.

Refreshingly, another article in the issue (about parking, no less) from Sharon Bosworth of Barracks Row Main Street gets at the real reason 8th St SE is more favorable to bars and restaurants instead of retail:

By mid 2009, The Wander Group, consultants who make saving America’s historic corridors their specialty, reported back to BRMS: our commercial corridor, specified by none other than Pierre L’Enfant in 1791, is today uniquely suited to businesses requiring small square footage because of the antique proportions of our buildings which are well protected in the Capitol Hill Historic District. Restaurants require small square footage and restaurant owners would always be on the hunt for charming, historic sites. Wander Group predicted more restaurateurs would find us, and so they did. Our tiny buildings are difficult (but not impossible) for most retail footprints, yet they work perfectly for restaurants.

In addition to those challenges, there’s the broader issues facing retail – online competition, fighting against the economies of scale for big box and chain retailers, etc.

Instead, we have an industry that works well in an urban setting and wants to cluster here.  Here’s one vote in favor of more corner bars.