Thursday, January 29, 2009

when cross-disciplinary studies go bad

I have long respected the work of the Santa Fe Institute, home to "multidisciplinary collaborations in the physical, biological, computational, and social sciences" in pursuit of an "understanding of complex adaptive systems," which are found everywhere from cells to cities. I was therefore disappointed by a recent article on Santa Fe Institute President Geoffrey West, who appears to believe that mankind is on the path to "imminent destruction" (to his credit, those are the journalist's words, not his.) Beyond the sensational conclusion, I was put off by the surprisingly questionable logic employed by the theoretical physicist and the disconnect between his conclusions and reality.

West is an expert in universal scaling laws, and has focused his recent research on "[understanding] the dynamics of organisms, their structure, their organization, how they grow, how they evolve, how they live and how they die." He adds, "I wanted to see in what way an elephant is just a blown up mouse or a blown up human being, or in what way we are just a blown up cell." West's research has succeeded in uncovering principles of scale: "the pace of life gets slower and slower the bigger you are - in a very systematic, predictable way. You can do this from ecosystems down to cells. All of biology, pretty much across the whole spectrum, obeys this kind of behavior." The differences between the mouse and the elephant exemplify these principles.

How do these principles hold up when applied to human societies? According to West, not well. Greater size in human societies, be they cities or firms, does not lead to greater efficiency. West concedes that larger human societies bring about more wealth produced per capita, but argues that as "the number of patents that are produced goes up, the greater the number of AIDS cases there are, the greater the number of crimes there are, and the greater the amount of pollution that is produced."

Whereas larger organisms will have less disease and consume less energy relative to its size, West found that disease and energy consumption did not decline, leading him to conclude that human societies do NOT benefit from economies of scale like organisms in nature. From West's perspective, human societies grow less efficient as they grow larger. In nature, large animals use less oxygen per gram of weight than small ones, while humans seem to have a unyielding demand for money (the connection between oxygen and money being that each is a "vehicle for transforming goods into something useful"). And while the pace of organisms slows with greater size, activities within human societies grow more rapid with size, from bank transactions to the speed of walking.

It's hard to know where to start in rebuttal. First, if we are to test the applicability of scaling laws in organisms to scaling laws in human societies, it's important to properly assign our roles and keep them consistent. This should be straightforward, as small organism: large organism what small society: large society.

I will note that West fails to maintain the integrity of this relationship; for instance, when he argues that the pace of societies speeds up with size (unlike organisms), he is not talking about society, but its components. The speed of walking or activity of humans within that society is not the speed of society. Individual human beings: society is analogous to cells: organism. Once again, human accumulation of money (in surplus of what is necessary for reasonable expectation of survival) is not analogous to organisms' consumption of oxygen. There are in fact numerous reasons why this analogy doesn't hold, but there's no reason to go beyond the logic found in an SAT handbook – the analogy is violated by comparing a part (man) with a whole (organism).

To restate, West is, in theory, comparing the scaling laws of organisms to the scaling laws of human societies, so the wholes are organisms and societies; analysis of the parts of the wholes (e.g., cells and humans) may indeed be relevant, but they must be contrasted with one another, not with the wholes, to maintain consistency.

Perhaps more striking than the bizarre logic employed is the contrast between the reality and West's perception of cities. He sees larger human societies as more inefficient, yet the greater the size of human settlements, the more efficient they are – whether we are talking about environmental impact or otherwise. He sees the prevalence of disease canceling out the wealth created by economies of scale, but in what world is this born out? Wealth creation has allowed those who participate in the economies of scale to live longer, better lives. Economy of scale has given societies more productive, healthier cells, to the benefit of the whole (the society) and its parts (man).

The societies and the people who are least healthy, the least productive, and the least well-off are those who are least able to participate in the economies of scale. They are the mice. Their lives are short, nasty and brutish. These people and these societies would love to cope with the problems West associates with societies of great scale, and few if any members of large societies would trade their New York residency for a few acres in New Guinea.

West misses an opportunity to demonstrate the scaling laws of organisms actually apply quite well to human societies. From cells to human beings, living things are better able to survive in large vehicles – be they organisms or societies. That is not say greater size is always evolutionary advantageous, but is to say the principles of greater efficiency and durability West found in large organisms applies to large societies as well.

Finally, as the article nears the end, West argues that human society is unsustainable because "the pace of life is constantly quickening and the time between major innovations is necessarily getting shorter." He apparently believes it's a bad omen that while "it may have taken 50,000 years to go from stone to iron, and it may have taken 100 years to go from steam and coal to oil … how long did it take to go from being dominated by computers to being dominated by information technology, as being distinct from computers?"

Wow. And the final head-scratcher: "Products are coming out one after another. I have in front of me this marvellous Mac, but it is already becoming outdated. It's not only that we are on this treadmill that is getting faster and faster, but we are accelerating it."

Perhaps I'm missing something, but I am not sure why any of this is supposed to worry me. Notice that there is no resource depletion argument being made: he's not arguing that we're going to consume our ecosystem into nothingness. Apparently, the human productivity and technological innovation that has come with larger webs of cooperation and exchange have put us on a path to disaster.

Given Mr West's credentials, I'm wary of being too critical
–especially, when judging his work through the lens of a journalist– but I am left at a loss. Read more!

Saturday, January 24, 2009

the city: good for migrants, bad for genes?

Arnold Kling and Richard Florida have recently started up blog conversation on whether cities are creative growth centers or urban death traps.

Kling quotes Razib Khan:

up until the year 1900 the world's cities were massive genetic blackholes. Cities only kept their population up through migration, which explains how Rome shrunk to 30,000 inhabitants by the 7th century.
Kling asks how this jives with Jane Jacobs, who contends that urban settlements have been the catalysts of economic growth. Jacobs isn't directly contradicted by the genetic data, but the two certainly appear to point in different directions. If cities were genetic graveyards up until 1900, how can it be that cities were simultaneously hubs of economic growth?

One way to reconcile the two perspectives is to restate Jacobs' position: when circumstances allow for economic growth, returns on agglomeration will concentrate this growth in urban settlements, which will in turn spur further development. Population density is not a guarantor of growth. Furthermore, when lacking the conditions necessary for growth, urban settlements' negatives, such as disease, may outweigh any benefits to agglomeration, leading to a relatively poor genetic expectancy.

The Jacobs question, however, really only touches on a more fundamental question: if cities were genetic graveyards, why did migrants continue to flock to these urban death traps?

Why were genetic returns to agglomeration negative during a period when economic returns were relatively high, according to Jacobs and historical migration patterns? What in the name of Charles Darwin was going on?

I'm interested in hearing theories (perhaps the immediate prospects for the migrant is better in the city, but their genes are more likely to be wiped out generations later by a plague...), but for now, I am skeptical that millions of people, throughout history, have lowered their genetic expectancy by migrating to urban death traps.
Read more!

Thursday, January 22, 2009

in defense of historical context

I was struck by a recent article by Ed Glaeser, which takes a historical look back at the policies and ideologies of politicians from Henry Clay to Woodrow Wilson.

While I generally find Glaeser's perspective to be in line with my own, I found his historical characterizations grating: positive depictions of Andrew Jackson and Woodrow Wilson, negative characterizations of Alexander Hamilton and Teddy Roosevelt -- yikes.

I can't claim complete objectivity in this matter, as the latter are two of my favorite American historical figures, and the former float around the bottom of my informal ranking of American presidents. For reasons distinct from his economic policy, Jackson may be one of the most despicable blemishes on our national record (I'll be reading the "American Lion" soon - we'll see if that sways me.)

But more significant than the details of Glaeser's particular article is what it represents, that is, a tendency amongst modern thinkers to distort the thoughts, motivations, and actions of past figures through a decidedly modern prism.

Many small-government folks will pick up the "Jeffersonian" mantle and sneer at Hamilton, with his love of federal power. Now, people do all sorts of crazy stuff, but this bothers me because I happen to otherwise agree with a lot of these people. Often these are disciples of Friedrich Hayek and Milton Friedman, who view the Hamiltonian legacy as a threat to state -and by extension- individual power.

These moderns have the nasty tendency of reading the words and actions of men and women (namely men) long since dead and gone as if they were writing and acting in the modern world. 'Hamilton - oh jeez, he loves federal power, he'd be all about expanding the reach of The Man at the expense our Ron Paul revolution!'

And so, these men of history are stripped of their historical context.

This is unfortunate. A careful consideration of context allows for a more precise understanding of the historical person, a more objective and apt judgment of their actions, and a sounder understanding of just what lessons to learn from their experiences.

Myself, I believe Hamilton's presence may have carried the second most weight in securing the United States' future prosperity and relative security while also believing that the US would currently benefit from a devolution of power from the federal to the state level (and from the government to the individual): there is no contradiction inherent in these positions.

The age of Hamilton saw the competition of great Atlantic nation-states. The countries were powerful, aggressive, and keen to elbow out competition and expand wherever they might find opportunity. (Just ask the Dutch Republic.) The American colonies were weak and divided, and, without Hamilton's supposedly nefarious central bank and consolidation of debts, would doubtlessly have drifted further apart.

Even with Hamilton's work, the United States had to fend off foreign intrigues that sought to play one state off the others to secure geopolitical and economic interests in America. Given the history of Europe, I feel confident speculating that a country with a Spanish Florida, British Texas/South, French Bayou, and/or Mexican/German/Japanese Pacific would have led to considerably more wars and considerably less economic growth.

My argument, by the way, implies that this added value also supports the westward expansion (unfortunately named 'Manifest Destiny') in the name of continental integrity (the later Mexican/German intrigue and Japanese hostilities would seem to support this logic), as well as forbidding the South from succession (a tricky issue likely deserving of its own post).

Economic liberty should be fought for and celebrated, and Americans are right to be suspicious of any actions that usurp this personal freedom in the name of fighting some greater enemy.

That does not necessarily mean that there are no times when such a sacrifice is not just wise, but necessary for the long-term preservation of this economic liberty. In the early 21st century, with the world's great states at rest and a federal government infinitely more powerful than its 18th century counterpart, there are few if any reasons to further concentrate power (and indeed many to devolve it). As noted above, Hamilton's America was an entirely different beast struggling to survive in a far different jungle. And just as evolution may favor a smaller or larger animal at different points of time, the same is true for the natural selection of human societies.

The intertwining fates of survival and liberalism are recent developments, and to attack figures like Hamilton for failing to live up to 20th century ideals is as silly as criticizing Caesar as a murderer of democracy. To say that circumstances vary widely is to understate the point: in many cases, it may be more effective to use different terminology for different periods of time, so as not to confuse common terms with common realities.

I should note that I don't mean this post to be a final word on the defense of Hamilton, but simply to raise a principled disagreement with the method by which he -and many others- are judged. Economists with no historical background can be just as inane as historians with no economic learning.

That said, I think the econs are right on about FDR. ;-)
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Thursday, January 8, 2009

three millenia of waste management

For the past few months I have searched high and low for a book that would provide me with a comprehensive understanding of the history of waste management in relationship to the rise and decline (or perhaps more appropriately, growth and diseased death) of human societies. This book would cover the history of sanitation, from aqueducts to soap to sewers, and explain how proper waste management acted as an upper bound on city growth, with failure resulting in biblical plagues that would wipe out entire towns and set back development hundreds of years.

I came across The Big Necessity and Flushed, among others -reading the latter and adding the former to an increasingly formidable "to-read" pile- but neither had the historical context I was looking for.

I then set about to leverage my limited knowledge and the endless information available on the internets to write a blog post on the matter (if I couldn't read it, perhaps I could write it...)

Up until the last couple hundred years, waste management amounted to nothing more than disjointed efforts -- e.g., Indus Valley, Greece, Rome -- with little relevance to the society's death or survival (sure, Rome reigned supreme at the time, but I've seen no reason to believe that their water works were the key to, rather than the the product of, this greatness).

My hypothesis, of course, is not that waste management leads to glory, but that waste management acts as an upper bound on the growth of human societies; at some point, a city's ability to support their population without falling prey to death and disease depends on waste management. As a further clarification, that is not to say that through adequate waste management a city can avoid the possibility of disease altogether: plagues have many vectors by which they can decimate a population, waste management will not eliminate them all.

This hypothesis jives with the lack of waste management innovation for most of the history of mankind. Looking at the population chart graphic, it's striking just how flat the world population was up until ~1500 - ~1800.

Now, world population growth does not necessarily mean city growth; for a city growth proxy, I took the average of the historical estimates for the top two most populous cities at various points in history:

100 AD Rome / Luoyang (Honan), China: 435,000
1000 AD Cordova, Spain / Kaifeng, China: 425,000
1500 AD Beijing, China / Vijayanagar, India: 586,000
1800 AD Beijing, China / London, United Kingdom: 980,500
1900 AD London, United Kingdom / New York, United States: 5,361,000
1950 AD New York, United States / London, United Kingdom: 10,661,500

Currently, Tokyo and Mexico City are Nos. 1 and 2, averaging ~23,000,000.

In this context, it should be no surprise that there was little development in waste management until the 19th century. Little changed in terms of the demands placed on waste management, and so the history of waste management up until the 19th century is nothing more than series of blips, for the most part.

That is not to deny that some societies appreciated the value and convenience of fresh and streaming water in a central location, however, which sometimes also involved proper waste management.

Water works got an early start, with the the Harappan constructing water systems in the Indus Valley in the third millenium BC. Everyone within the town walls -not just the elite- had running water and indoor plumbing.

Outside of the Romans, there would be little improvement over this flash of brilliance until the 19th century (~4500 years). In the mean time, the Persians developed qanats (like aqueducts, but for agriculture); a Minoan ruler built a luxurious castle in Crete with running water and primitive toilet; and finally the Greeks began capitalizing on aqueducts in the 4th century, setting the stage for the Romans.

The Romans' passion for plumbing grew out of a greater love for baths. The city's plumbers utilized lead (in place of terracotta and other materials) to construct the pipes of the aqueducts, which were built to provide a continuous flow of water to foundations and the baths.

In a trend that continues even up through the 19th century, waste management systems were not created to deal with health issues. Convenience and luxury bear most of the credit for the innovations that did take place. The science of sanitation simply did not exist.

Now I must take a moment to talk about the plagues that struck some of the world's greatest cities before 1800. First, before the Black Death struck down ~400 million in the 14th century (with additional waves sweeping Europe and elsewhere for hundreds of years), the bubonic plague decimated the emperor Justinian's Byzantine empire in 541-542 AD. In both cases, it appears disease spread was spread through fleas and rats, which many speculate came to their new homes free-riding on merchant ships.

These plagues may have been the first large-scale tests of waste management. Would a 21st century sewage system have saved any of these cities? I'm no expert, but surely the plague would still have made an appearance. The effects, however, would likely have been far less devastating with the appropriate disposal of diseased bodies and waste.

For instance, one of the few places with plumbing, Canterbury monastery, escaped unscathed during the darkest days of the plague in London.

But still, the science of sanitation remained a mystery, and no lessons were learned form the terrible episodes.

The waste management innovations that did eventually emerge were not thoughtful responses to newfound health risks, but responses to superficial concerns.

In the 1800s in England, water closets (think toilets) were popular luxury items amongst the have's. These water closets should not be confused with advances in waste management. Quite the contrary, as the water closets grew more popular, more waste emptied into the rivers.

(Fun fact from Flushed: sewers originally only meant waterways for drainage, it was only after they became deluged in feces that the word took its modern meaning.)

In this same period, cholera devestated London, and England's mortality rate rose close to 50%,.

Yet if a plague devestating the entire citycouldn't incite a change in waste management, infants dying of dirty water certainly wouldn't do trick. It would take the "Great Stink" of the summer of 1858, which saw the Thames' stench drive Londoners out of the city and, more impressively, drive the Houses of Parliament, which sit on the Thames, to act.

Dead babies were a problem, putrid stench was unacceptable.

Parliament empowered Joseph William Bazalgette, a civil engineer, to construct a sewage network. Bazalgette's system survives today, and successfully ended London's woes, even making the Thames fishable after decades of dead, diseased water.

At the same time, from 1840 to 1870, the number of communities with water works increased from 50 to 240. Shortly thereafter, the British OK'd public water closets, and inventors brought to bear the innovations that would become the world's modern toilets.

And so the stench of feces set in motion the development of the modern sewer system and the principles of separating the water that goes in from the stuff that comes out.

But just in case you thought that 20th century innovations in waste management would be rooted in medical knowledge, it would take a powerful Boston politico stepping in poop while running around Quincy before the cesspool known as Boston Harbor would be cleaned up in the 1980s.

And here we are, 4600 years after the Indus Valley civilization set a standard for indoor plumbing that was largely ignored up until the late 19th century. While I am troubled that we still haven't guaranteed this basic standard to every man, woman, and child alive today, I am struck by the remarkable progress we have made in the past 150 years, as well as disappointed how small of a role understanding of health risks played in the creation of the waste systems that could have been created hundred of years earlier.

I'm not sure what exactly to take away from the history of waste management, but it is both troubling and fascinating nonetheless.

Read more!