But unlike animals, cities do not slow down as they get bigger. They speed up with size! The bigger the city, the faster people walk and the faster they innovate. All the productivity-related numbers increase with size---wages, patents, colleges, crimes, AIDS cases---and their ratio is superlinear. It's 1.15/1. With each increase in size, cities get a value-added of 15 percent. Agglomerating people, evidently, increases their efficiency and productivity.
Does that go on forever? Cities create problems as they grow, but they create solutions to those problems even faster, so their growth and potential lifespan is in theory unbounded.
...
Are corporations more like animals or more like cities? They want to be like cities, with ever increasing productivity as they grow and potentially unbounded lifespans. Unfortunately, West et al.'s research on 22,000 companies shows that as they increase in size from 100 to 1,000,000 employees, their net income and assets (and 23 other metrics) per person increase only at a 4/5 ratio. Like animals and cities they do grow more efficient with size, but unlike cities, their innovation cannot keep pace as their systems gradually decay, requiring ever more costly repair until a fluctuation sinks them. Like animals, companies are sublinear and doomed to die.

From a Stewart Brand summary of research by Geoffrey West.

From a long conversation with West at Edge:

Let me tell you the interpretation. Again, this is still speculative.
The great thing about cities, the thing that is amazing about cities is that as they grow, so to speak, their dimensionality increases. That is, the space of opportunity, the space of functions, the space of jobs just continually increases. And the data shows that. If you look at job categories, it continually increases. I'll use the word "dimensionality." It opens up. And in fact, one of the great things about cities is that it supports crazy people. You walk down Fifth Avenue, you see crazy people, and there are always crazy people. Well, that's good. It is tolerant of extraordinary diversity.
This is in complete contrast to companies, with the exception of companies maybe at the beginning (think of the image of the Google boys in the back garage, with ideas of the search engine no doubt promoting all kinds of crazy ideas and having maybe even crazy people around them).
Well, Google is a bit of an exception because it still tolerates some of that. But most companies start out probably with some of that buzz. But the data indicates that at about 50 employees to a hundred, that buzz starts to stop. And a company that was more multi dimensional, more evolved becomes one-dimensional. It closes down.
Indeed, if you go to General Motors or you go to American Airlines or you go to Goldman Sachs, you don't see crazy people. Crazy people are fired. Well, to speak of crazy people is taking the extreme. But maverick people are often fired.
It's not surprising to learn that when manufacturing companies are on a down turn, they decrease research and development, and in fact in some cases, do actually get rid of it, thinking "oh, we can get that back, in two years we'll be back on track."
Well, this kind of thinking kills them. This is part of the killing, and this is part of the change from super linear to sublinear, namely companies allow themselves to be dominated by bureaucracy and administration over creativity and innovation, and unfortunately, it's necessary. You cannot run a company without administrative. Someone has got to take care of the taxes and the bills and the cleaning the floors and the maintenance of the building and all the rest of that stuff. You need it. And the question is, “can you do it without it dominating the company?” The data suggests that you can't.

Lastly, from an article about West and his research in the NYTimes.

The mathematical equations that West and his colleagues devised were inspired by the earlier findings of Max Kleiber. In the early 1930s, when Kleiber was a biologist working in the animal-husbandry department at the University of California, Davis, he noticed that the sprawlingly diverse animal kingdom could be characterized by a simple mathematical relationship, in which the metabolic rate of a creature is equal to its mass taken to the three-fourths power. This ubiquitous principle had some significant implications, because it showed that larger species need less energy per pound of flesh than smaller ones. For instance, while an elephant is 10,000 times the size of a guinea pig, it needs only 1,000 times as much energy. Other scientists soon found more than 70 such related laws, defined by what are known as “sublinear” equations. It doesn’t matter what the animal looks like or where it lives or how it evolved — the math almost always works.
West’s insight was that these strange patterns are caused by our internal infrastructure — the plumbing that makes life possible. By translating these biological designs into mathematics, West and his co-authors were able to explain the existence of Kleiber’s scaling laws. “I can’t tell you how satisfying this was,” West says. “Sometimes, I look out at nature and I think, Everything here is obeying my conjecture. It’s a wonderfully narcissistic feeling.”

The pace of technology has already shifted some of the old company scaling constraints in the past two decades. When I first joined Amazon, one of the first analyses I performed was a study of the fastest growing companies in history. Perhaps it was Jeff, perhaps it was Joy (our brilliant CFO at the time), but someone had in their mind that we could be the fastest growing company in history as measured by revenue. Back in 1997, no search engine gave good results for the question "what is the fastest growing company in history."

Some clear candidates emerged, like Wal-Mart and Sam's Club or Costco. I looked at technology giants like IBM and Microsoft. Two things were clear: most every company had some low revenue childhood years when they were finding their footing before they achieved the exponential growth they became famous for. Second, and this was most interesting to us, many companies seemed to suffer some distress right around $1B in revenue.

This was very curious, and a deeper examination revealed that many companies went through some growing pains right around that milestone because smaller company processes, systems, and personnel that worked fine until that point broke down at that volume of business. This was a classic scaling problem, and around $1B or just before it, many companies hit that wall, like the fabled 20 mile wall in a marathon.

Being as competitive as we were, we quickly turned our gaze inward to see which of our own systems and processes might break down as we approached our first billion in revenue (by early 1998 it was already clear to us that we were going to hit that in 1999).

Among other things, it led us to the year of GOHIO. Reminiscent of how, in David Foster Wallace's Infinite Jest, each year in the future had a corporate sponsor, each year at Amazon we had a theme that tied our key company goals into a memorable saying or rubric. One year it was Get Big Fast Baby because we were trying to achieve scale ahead of our competitors. GOHIO stood for Getting Our House In Order.

In finance, we made projections for all aspects of our business at $1B+ in revenue: orders, customer service contacts, shipments out of our distribution centers, website traffic, everything. In the year of GOHIO, the job of each division was to examine their processes, systems, and people and ensure they could support those volumes. If they couldn't, they had to get them ready to do so within that year.

Just a decade later, the $1B scaling wall seems like a distant memory. Coincidentally, Amazon has helped to tear down that barrier with Amazon Web Services (AWS) which makes it much easier for technology companies to scale their costs and infrastructure linearly with customer and revenue growth. GroupOn came along and vaulted to $1B in revenue faster than any company in history.

[Yes, I realize Groupon revenue is built off of what consumers pay for a deal and that Groupon only keeps a portion of that, but no company takes home 100% of its revenue. I also realize Groupon has since run into issues, but those are not ones of scaling as much as inherent business model problems.]

Companies like Instagram and WhatsApp now routinely can scale to hundreds of millions of users with hardly a hiccup and with many fewer employees than companies in the past. Unlike biological constraints like the circulation of blood, oxygen, or nutrients, technology has pushed some of the business scaling constraints out.

Now we look to companies like Google, Amazon, and Facebook, companies that seem to want to compete in a multitude of businesses, to study what the new scaling constraints might be. Technology has not removed all of them: government regulation, bureaucracy or other forms of coordination costs, and employee churn or hiring problems remain some of the common scaling constraints that put the brakes on growth.