Challenging the Scale

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Have you ever read the book “Scale” by Geoffrey West? An excellent read, and I completely disagree with most of what it has to say. I think that if you’re engaged in urban planning you owe it to yourself to read it. That book was actually one of the first sparks that ignited this very blog.

Let’s put my reservations in perspective – the urban environment; the book describes it very well but I think it completely misses the mechanism and model behind it. It is quite easy to disprove the model presented in the book and I have a feeling that the author knew it. Most of the book does not deal with cities but rather explains the mathematical thinking behind “Scaling” lows. The way organisms and organizations vary depending on their size. In the section that relates to cities the book begins with a great momentum while describing urban behavior but stumbles when it comes to the big question – Why the hell is it happening?

Link to the book in Amazon:

In this article I would like to directly challenge the assumptions the author made in his analysis regarding cities. Note, I do not dispute the numbers and findings but rather the theory and the model explaining them.

The main problem with the model is that it compares cities to mammals. An ill-advised comparison considering … a city is not an independent creature.

A mammal is an economically isolated creature. It has a set amount of energy it needs to live and the amount it can produce from the food it eats. It would not help a mammal if his neighbor ate more and it will not die if it’s neighbor starves. Blood cells do not pass from one mammal to another.
In contrast to it, among cities “energy exchange” certainly happens. Residents move from one city to another, factories in one city sell their products in another, and so on. You are, for example, scanning now through text and receiving information created on a two years-old laptop inside a private house in a tiny suburb near a small town in the country where people write from right to left. We are having an exchange of information and money between cities, “economic energy” if you will.

The best biological equivalent for cities can be also found in the book but the author avoids it for some reason. It is possible and more appropriate to compare cities to parts of the vascular system or to a tree. In the book you can find that in most countries the size of the cities tends to match this idea. There is one very big city (the aorta, or the stem of the tree), there are 2 of cities about half that size, 4 with the size of a quarter, eight the size of an eighth, and so on. This fact is not a new discovery(and I’m simplifying it of course) but the principle is true.

The model for cities should consider the whole country, the grander economic entity, and incorporate the fact that economic energy flows from city to city. Yes, yes, I know. In the age of globalization, the state is not an isolated entity either. I will go into that in the chapters about globalization.

It may seem that the economic model behind the cities does not really matter. What difference does it make if we think about them as different mammals (mouse, horse, whale) or different parts of a tree (stem, branch, twig)? Yet this is not a minor issue at all. In fact, this is a critical part of our understanding of the spatial market.

As individual mammals, a blue whale does not care how many horses starves or flourish. But will New York’s economy be affected if all second-tier cities cease to exist? of course! It depends on them entirely. The New York Stock Exchange does not speculate on New York companies alone. The whole economic oxygen NY has comes from outside. We can never understand what is a city, what causes it to grow and what can kill it , if we do not agree on these models.

Kill a city

And that, is another point of contention I have with the book. It presents cities as immune to everything. After all, even an atomic bomb did not erase Hiroshima for a long time. Twenty years after the war the city was rebuilt and grew further.

Really? Cities never die? Do you need me to answer that?

What do you think about the towns along Route 66 in the US? Would you like me to show you the ruins of cities along the ancient Silk Road ? To end a city is as easy as it is to kill a tree branch. Just tighten a rope, shut the bloodline leading to it and soon enough the city will die of gangrene and fall.

A cat can live alone. A city can not exist alone. Without roads leading to it, without supply of economic oxygen the city will die. Any Roman emperor knows – Rome is as great as the roads leading to it.

In another part of the book the author is misinterpreting cities as he is examining only at the very near history and the very large cities, while the world population grows. It is like looking only at big companies in the Stock Exchange during an economic boom – they all prevail, none is discarded, so companies are probably indestructible.

The right way is to regard companies relative to the market index. What does it matter if the company survived and achieved a profit of 3% if the market did 30% at that same year? In the same manner, what does it matter if small cities remained with the same number of residents for 20 years if the number of residents in the country increases by 20%? The writer looks at a period of time that is too short for a city’s life and ignores the tide of the market.

In fact, cities today are under tremendous economic pressure. If we were not in a state of accelerating growth, we would have easily noticed that many of those peripheral towns and small cities are already in the stage of advanced necrosis.

The Godzilla city

The book explains why mammals have a minimum and maximum size. Why the largest mammal that can be is about the size of a whale and why there can not be a mammal the size of King Kong or Godzilla. I will not go into all the explanations here but I want to focus on one that relates to the vascular system. The vascular system is built so that there is a limit to how many cells can be provided with oxygen. Even a very effective heart, with wide arteries that divide and divide up to the capillaries and feed the individual cells, can not push blood beyond a certain size. And without blood there is no oxygen, without oxygen there is necrosis and death of the cell.

The Author claims that mammals have a limit and can not be “Godzilla”. But as New York is a Godzilla of a city, and as London, Tokyo and many other cities are at a size we’ve never seen before, Therefore, he claims that the urban model differs from the vascular model.

So … if a model of a tree or vascular system fails to explain huge cities why am I presenting it as the biological equivalent?

Here comes the second issue in which I challenge the book – What created those huge cities?

In my opinion, the vascular model works here very well. All you need to do is simply pay attention to the details constructing it. The size limit in the vascular system is derived from the fluidity of the blood, the elasticity of the veins and the mechanical and physical properties of the system.
But what if the blood is less viscous? What if the veins are made of titanium rather than flexible tissue? What if the final passage to the cell will not be a slow crawl of blood pressure from the heart but increased with a secondary pump?

You got it. The model remains the same and we can get Godzilla. In fact, we’ll create Godzilla whether we like it or not.

Our cities depend on veins and arteries that transport oxygen. This oxygen (people, money, data and goods) must reach every corner of the city. A place where those do not arrive will die.
But if we stop traveling in carts pulled by horse and start using cars? If we pave the roads with asphalt replacing gravel roads? If we add elevators that allow us to build huge buildings … and airplanes, and trains, and buses and bicycles … The blood in the system runs at higher speeds, in quantities that were never possible before, and Godzilla raises its head and gazes at the new world.

The city is an economic model just like the vascular system. The reason we “suddenly” see huge cities is exactly because of it – we have changed the parameters of the blood vessels. We made them more efficient, changed their mechanical and physical properties but remained with the same topological organization and hierarchy – stem, branches, twigs.

My conclusion is therefore different from the conclusion presented in the book. The writer presents the growth in cities as something made possible due to invention, I claim it to be an unavoidable byproduct of inventions used to advance the exchange of wealth. If we move money, people and data faster, it changes the veins’ abilities and we get an even bigger city. Wooden ships? Elevators? Cars? Any major improvement in transport leads to a correlating urban shock wave.

There are also ways for ”Myocardial infarction” in the transmission system, intentionally created or otherwise. Traffic jams, snowstorms, demonstrations, custom tax and more. Usually these can be found in places and frequency that we can afford. New York, for example, is virtually unaffected by the existence of the NY marathon once a year. If it had 24 such events each year, quite a few businesses would have preferred to build their offices in New Jersey.

The Last comment I want to make about this biological equivalent for cities is that I think there is actually a better model for the city economy, a physical one rather than a biological one. I think that the proper model that allows us to understand the city is a gravity model.  There are other differences between the model I present and the model presented in the book, but their consequences are secondary to those above.


Unfortunately, I also agree with the book’s author on some subjects. I despise smart people who thought about things before I did. I Admire them, envy them and hate them at the same time.

The system can not grow that way forever.
Following the same principles with the same mathematical concept, I also find the accelerating growth we see today as something that can not last forever. Like the author, I also hope that it will end with a slowdown and stabilization, a paradigm shift and not a collapse, we both look at the future with some fear in our eyes.

My editor says I’m petty… he may be right.

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