Collapse or Longevity? Failure or Success?

When many people think of the ancient Maya, the term "collapse" often comes to mind. The Mayas were a group that were around for a while, but then collapsed. Archaeologists have spent a lot of time (and a lot of fieldwork and publications) trying to figure out how or why (or sometimes, whether) the Maya collapsed. If they collapsed, there must have been something wrong with Maya society, right? But the Maya cities lasted for some seven centuries before they were abandoned. Think about it. Seven hundred years. Were the Maya a failure (they collapsed), or were they a spectacular success (they lasted 700 years).

The idea that something must have been wrong with ancient cities or civilizations to make them collapse is a popular notion. And while it is a valid question to ask how or why a society like the Classic Maya collapsed, any such question should be paired with a consideration of just how long they managed to thrive. This collapse bias surfaced again today in a paper just posted in the Proceedings of the National Academy of Sciences:  "Human domination of the biosphere: Rapid discharge of the earth-space battery foretells the future of himanking" by Rohn R. Schramski, David K. Gattie and James H. Brown. This is a fine paper, about the global chemical energy supply on earth, and how it is being depleted at an incredibly fast rate right now. But they had to throw in a dig at ancient societies:

At local and regional scales, many multiple past civilizations (e.g., Greece, Rome, Angkor Wat, Teotihuacan) failed to adapt to changing social and ecological conditions and crashed catastrophically

Let's take a different look at those four ancient societies in comparison to contemporary nation-states:
 

So, which of these societies seem successful, and which ones seem too young to judge? I am dating the start of the European nation-states to 1648, the signing of the Treaty of Westphalia which created the modern system of nation-states. If European nations manage to survive another half century or so, they will have matched the longevity of ancient Greece (I am using the Classical and Hellenistic periods here). And if they last another 350 years they will match those failed collapsers, the ancient Maya.

I am the last one to deny the significance of the Classic Maya collapse. I think the revisionists who claim that they didn't really collapse are just plain wrong (see some of my posts on Publishing Archaeology about this, such as this one about Jared Diamond and his critics). But if the Maya managed to thrive in the jungle for seven centuries, maybe that fact should outweigh their eventual collapse. They spent centuries doing many things right, and then they got trapped for a few crucial decades and collapsed.

I will just chalk up the collapse quote above to the fact that scholars outside of history and archaeology tend to be clueless about ancient societies. I think the authors of the new paper are correct when they claim that ancient collapses "are of questionable relevance to the current situation." Much as I'd like to believe that the sustainability (or lack thereof) of ancient societies might have lessons for us today, in fact the technological, energetic, and demographic situation today is radically different from that of ancient societies like the Maya. I do think that ancient cities and societies have lessons for us today, and that is a major theme of this blog. But the nature of overall societal sustainability may not be one of those lessons.

How do big cities differ from small cities (in the ancient past and today)?

Are big cities different from smaller cities mainly in their size? Or do they differ in other ways that go beyond simple population size? Recent research on urban scaling has answered this question definitively for contemporary cities. Large cities ARE different from smaller cities in ways that transcend their size. They aren't simply larger. Yet many of the changes that come with size turn out to be linked systematically to population size.

For example, large cities of course have more miles of roads and and electrical cables than smaller cities. But when we look at roads or cable per person (miles per capita), the quantities are smaller for the biggest cities. This makes sense: if you have twice as many people in a city, you don't need twice as many roads, since some of the new people can use existing roads. While this much is obvious, quantitative research in urban scaling reveals a surprising finding: the way that the miles of roads per person changes with city size is extremely regular. The same quantitative relationship holds if you are studying cities in the U.S., in Europe, or other parts of the world. There is a basic underlying regularity to the quantities of urban infrastructures that get built and used, in cities all over the world.

Other types of regularities have been found by the urban scaling researchers. First, big cities have denser populations than smaller cities. One way to view this is that the areal extent of cities grows more slowly than does the population. The result is an increasing population density in larger cities. But again, this patterns is extremely regular and predictable mathematically. Second, the most remarkable regularity identified by urban scaling has to do with socioeconomic outputs. Whether you measure income, wealth, innovation, crime, poverty, or the number of rock bands, these features all increase more rapidly than does the population size. Big cities not only have more rock bands than smaller cities, but they have more rock bands PER PERSON than smaller cities. Furthermore, the mathematics are predictable. The rates of rock bands--or poverty, or patents--per person follow a very regular quantitative pattern.

Why is this? The basic idea is that as city population grows, so too does the number of social interactions among the residents and visitors to the city. But the number of potential  social interactions can increase at an exponential rate. And these interactions generate information and change. One basic metaphor is to say that cities are social reactors. They magnify the benefits (and negative consequences) of social interactions.

So far, I have been describing urban scaling research on modern cities. See the works of Luis Bettencourt and his colleagues listed below for more information, or see my earlier post on this research. But what about cities and settlements before the modern era? A new paper, published today, provides new evidence that similar predictable quantitative patterns are found in ancient cities. That is, Precolumbian settlements in central Mexico exhibit the same quantitative regularities in population density and social outputs as modern cities. Of course the society, the economy, and the nature of cities were very different back then. But still, the same quantitative patterns are present. To me, this is a remarkable finding.  The paper is:

Ortman, Scott G., Andrew H.F. Cabaniss, Jennie O. Sturm, and Luís M. A. Bettencourt   2015    Settlement Scaling and Increasing Returns in an Ancient Society. Science Advances 1(1).

This is an update and extension of their prior paper:

Ortman, Scott G., Andrew H.F. Cabaniss, Jennie O. Sturm, and Luís M. A. Bettencourt   2014   The Pre-History of Urban Scaling. PLOS-one 9 (2): e87902.

The authors analyze settlement size and other data from the Basin of Mexico Archaeological Survey Project  (Sanders et al, 1979), and find that the quantitative patterns match those predicted by models of urban scaling that were first worked out for contemporary cities (Bettencourt 2013). I find this line of research fascinating, to the extent that I have been measuring cities and the sizes of their central plazas to investigate the quantitative pattern. It turns out that the size of the central plaza relates to the overall city size in a quite regular pattern, but the form of the equation does not match any of the quantities measured for modern cities. Hmmmmmmmm. I'll write more on this later.

For now, the new paper by Ortman et al is important for several reasons:

1. It provides new data on quantitative patterns in the ancient cities and settlements of the Basin of Mexico.
2. The results compare rather precisely to the predictions of the models and to the data on modern cities.
3. This work shows the value of archaeological data for answering interesting questions about cities and urbanism in the past and the present. This only works when the original fieldwork was done well, and when the data are published and made available to other scholars.

Here are some publicity and news items about today's new paper:

An article by Emily Conover in Science Online

An article by Megan Gannon in LiveScience. 

Press release from the Santa Fe Institute

Bettencourt, Luís M. A.
2013    The Origins of Scaling in Cities. Science 340: 1438-1441.

Bettencourt, Luís M. A., José Lobo, Dirk Helbing, Christian Kühnert, and Geoffrey B. West
2007    Growth, Innovation, Scaling, and the Pace of Life in Cities. Proceedings of the National Academy of Sciences 104: 7301-7306.

Bettencourt, Luís M. A., José Lobo, Deborah Strumsky, and Geoffrey B. West
2010    Urban Scaling and its Deviations: Revealing the Structure of Wealth, Innovation and Crime Across Cities. PLoS One 5 (11): 1-9.

Sanders, William T., Jeffrey R. Parsons, and Robert S. Santley
1979    The Basin of Mexico: Ecological Processes in the Evolution of a Civilization. Academic Press, New York.

How ancient cities can help us understand modern cities

Tropical sprawl at Angkor (Evans et al. 2013)

A growing number of archaeologists, including me, believe that the results of our excavations at
ancient cities can help us understand cities today. The problem is that the road from, say, a  map of an ancient Mesopotamian city or the trash heap next to one of the Aztec urban houses I've excavated, to information relevant to modern cities, can be long and difficult. The popular press and university public relations offices are quick to draw facile modern connections for research on ancient cities. Mapping the huge city of Angkor revealed low-density settlement, so this helps us understand urban sprawl. Tell Brak, a much earlier city in Mesopotamia, also had low-density settlement, and the Environmental News Network reports that "Researchers [at Tell Brak] rewrite the origins of ancient urban sprawl" (for these and other examples, see Smith 2010, p. 229).

The implication of these press reports seems to be that urban planners in southern California might read about Angkor or Brak, and this will help them deal with with urban sprawl and its consequences around Los Angeles. I don't think so. The actual situation is much more complex. I will discuss this with respect to four questions:

The earliest sprawl? Tell Brak (Ur et al. 2007)

1. How, exactly, are ancient cities be relevant to contemporary urbanization?

I gave my take on this question in an earlier post,"Why are premodern cities important today?" (2011). To summarize here, there are two main arguments, that I call the urban trajectory argument and the sample size argument.

The urban trajectory argument. This has two components, the long and the short perspective. The long perspective argument suggests that having a broad historical perspective, looking a cities from deep history to the present, helps us understanding cities and how they change through time. One statement of this argument is the quote from Winston Churchill at the top of this blog: "The farther back we look, the farther ahead we can see."

The short perspective argument says  that to understand cities today, we need to know how they developed historically. Richard Harris and Robert Lewis (1998) make this point for the value of (recent) urban history in understanding North American cities today. But if we go back earlier in time, then archaeological studies of, say, Aztec cities, can help reveal the forms and functions of early Spanish cities that were created as replacements for, or transformations of their Aztec antecedents. Setha Low (1995) discusses this issue. The fact that archaeology covers long periods of change through time is what gives it special insights into trajectories of urban change.

Coatetelco, an Aztec city (Smith 2008)

The sample size argument.  Again, there are two parts to this argument. First, adding ancient cities to the body of knowledge of contemporary and historical cities provides a broader base for generalization and explanation. By widening the comparative framework of cities, archaeological findings help scholars distinguish the unique from the universal, they provide additional insights on specific cities, and they help in uncovering the dynamics of change and causality. What forces shape urban development and how do they operate? The bigger and more diverse the sample, the better we can answer this and other questions.

The second part of the sample size argument is that by providing more and more diverse examples of cities, knowledge of ancient cities give modern planners and managers more case studies to draw on.

2. Do archaeologists have the data to illuminate urban trajectories and increase the sample of known cities?

The answer here is both yes and no. Archaeologists have excavated and mapped and analyzed many ancient cities from all over the world, and we have lots of data that bear on a wide variety of urban issues, from neighborhoods to sprawl to economic growth. The problem is that we haven't analyzed our data in ways that allow direct examination of these issues, or ways that allow comparison with modern cities. I published a paper in 2010 on precisely this issue: "Sprawl, Squatters, and Sustainable Cities: Can Archaeological Data Shed Light on Modern Urban Issues." For me, this is one of the most frustrating aspects of trying to compare ancient and modern cities. Archaeological data can be messy and difficult to work with. The way we analyze and publish our data are rarely of direct relevance to contemporary social issues. We need to reanalyze our findings, using the concepts, methods, and data formats that relate to research on contemporary cities and society, and that takes time and effort. Will archaeologists do this?

3. Will archaeologists do the work to translate our data into usable formats?

I am optimistic that some archaeologists will make the effort to translate the results of our fieldwork into findings that can be used and understood by other urban scholars, by policy makers, and by the public. Indeed, an important new paper by a group of prominent archaeologists came out this week in the journal American Antiquity, with a summary in the Proceedings of the National Academy of Sciences (Kintigh et al. 2014). These authors identify 25 "grand challenges" for archaeology in the near future. (See my take on the list of challenges here). These are big questions, amenable to archaeological research, that relate to major intellectual and scientific issues today. One of these challenges concerns cities and urbanism, Challenge A6: "How can systematic investigations of prehistoric and historic urban landscapes shed new light on the social and demographic processes that drive urbanism and its consequences?" And several others overlap considerably with urbanism, including a challenge on social inequality (# A2) and two on the nature of human communities (# A4 and A5).

I am excited by this new list of grand challenges for archaeology, and the inclusion of cities and urbanism in several of them will help stimulate further archaeological research on ancient urbanism and its contemporary relevance. The authors cite my 2010 paper in their discussion of the urbanism challenge. More and more archaeologists are starting to realize the value of reanalyzing our data to address new and important research questions. Indeed, this is one of the explicit reasons for identifying research challenges: where should we concentrate our effort beyond our regular fieldwork?

Phoenix

I know this difficulty of translating archaeological findings first-hand. I am trying to get some of my own archaeological data into usable formats, and it is taking far too long. I can get grants for fieldwork and artifact analysis, but rarely for this kind of data analysis, so I have to work on this in my spare time (I have two grant-funded projects that take up most of my research time). Since I don't have funding to hire student Research Assistants for this kind of work, I have to go with the help of undergraduate interns and volunteers. I am fortunate in having a great group of undergraduates (and graduate students) in my university lab to help with these tasks, and we are moving ahead, slowly but surely.

4. Who needs to look at archaeological findings?

When you read the press releases about how Teotihuacan is valuable for understanding urban planning, or how Angkor illuminates sprawl, you sometimes get the impression that planners and politicians are going to read archaeological reports and this will help them with their jobs. Well, think again. The mayor of Phoenix is not going to give me a ring and ask my advice on how to improve the marginal neighborhoods in South Phoenix, on the basis of my archaeological research on ancient neighborhoods. But Phoenix planners are far more likely to consult the broader social science research on neighborhoods to help with ideas and plans. They may look at Robert Sampson's 2012 book, Great American City, or Sidney Brower's 2011 book, Neighbors and Neighborhoods. And I'd hope they wold also look at other neighborhood research, such as Emily Talen's (2010) paper on diverse neighborhoods.

Given this situation, my strategy has been to try to get ancient cities onto the radar of scholars and others interested in cities and urbanism from a broad perspective. I've been publishing in urban journals outside of archaeology, giving papers at conferences, and generally trying to make other urban scholars aware of the potential value of archaeological data on ancient cities (see Smith 2012). This is one of the reasons for writing this blog. I like to ask questions such as,"Why are Aztec cities interesting?" (2012); that is, why are they interesting in comparison to other known ancient and modern cities? These efforts are starting to pay off; Sampson has cited my work in several publications as supporting the notion that neighborhoods are enduring and long-lasting.

But the first step is to recognize that ancient and modern cities are both part of a single category--cities. Knowledge from one urban realm can be applied to another realm, for the improvement of our general understanding of urbanism. All cities, from ancient Uruk to contemporary Mumbai, are part of this wide urban world.

Dharavi slum in Mumbai

References:

Brower, Sidney N.  (2011)  Neighbors and Neighborhoods: Elements of Successful Community Design. APA Planners Press, Chicago.

Evans, Damian H., Roland J. Fletcher, Christophe Pottier, Jean-Baptiste Chevance, Dominique Soutif, Boun Suy Tan, Sokrithy Im, Darith Ea, Tina Tin, Samnang Kim, Christopher Cromarty, Stéphane De Greef, Kasper Hanus, Pierre Bâty, Robert Kuszinger, Ichita Shimoda and Glenn Boornazian  (2013)  Uncovering archaeological landscapes at Angkor using lidar. Proceedings of the National Academy of Sciences 110:12595-12600.

Harris, Richard and Robert Lewis  (1998)  How the Past Matters: North American Cities in the Twentieth Century. Journal of Urban Affairs 20:159-174.

Kintigh, Keith W., Jeffrey Altschul, Mary Beaudry, Robert Drennan, Ann Kinzig, Timothy Kohler, W. Frederick Limp, Herbert Maschner, William Michener, Timothy Pauketat, Peter Peregrine, Jeremy Sabloff, Tony Wilkinson, Henry Wright and Melinda Zeder  (2014)  Grand Challenges for Archaeology. American Antiquity 79(1):5-24.

Kintigh, Keith W., Jeffrey H. Altschul, Mary C. Beaudry, Robert D. Drennan, Ann P. Kinzig, Timothy A. Kohler, W. Frederick Limp, Herbert D. G. Maschner, William K. Michener, Timothy R. Pauketat, Peter Peregrine, Jeremy A. Sabloff, Tony J. Wilkinson, Henry T. Wright and Melinda A. Zeder  (2014)  Grand Challenges for Archaeology. Proceedings of the National Academy of Sciences 122:879-880.

Low, Setha M.  (1995)  Indigenous Architecture and the Spanish American Plaza in Mesoamerica and the Caribbean. American Anthropologist 97:748-762.

Sampson, Robert J.  (2012)  Great American City: Chicago and the Enduring Neighborhood Effect. University of Chicago Press, Chicago.

Smith, Michael E.  (2008)  Aztec City-State Capitals. University Press of Florida, Gainesville.

Smith, Michael E.  (2010)  Sprawl, Squatters, and Sustainable Cities: Can Archaeological Data Shed Light on Modern Urban Issues? Cambridge Archaeological Journal 20:229-253.

Smith, Michael E.  (2012)  The Role of Ancient Cities in Research on Contemporary Urbanization. UGEC Viewpoints (Urbanization and Global Environmental Change) 8:15-19.

Talen, Emily  (2010)  The Context of  Diversity: A Study of Six Chicago Neighbourhoods`. Urban Studies 47:486-513.

Ur, Jason A., Philip Karsgaard and Joan Oates  (2007)  Early Urban Development in the Near East. Science 317:1188.

"Connecting Past and Present:" Cities and global environmental change

"Connecting Past and Present: Lessons in Urbanization and the Environment." This is the title of a special section of three articles in the new issue of UGEC-Viewpoints. This newsletter/magazine is put out by the project, "Urbanization and Global Environmental Change," which in turn is part of a larger research network called "International Human Dimensions Programme on Global Environmental Change."

These three papers lay out some of the basic arguments for why ancient cities might be relevant for understanding contemporary urbanization and its environmental impact today. The phrase "might be relevant" is important; I will return to it below.

The section starts off with my paper, "The Role of Ancient Cities in Research on Contemporary Urbanization."
I ask, "Why should researchers in this area pay attention to ancient cities?" and I suggest two reasons. First, the long-term perspective of archaeological data lets us look at cities that rose and fell over period of centuries and millennia. Second, ancient cities add to our sample of urban possibilities, allowing a broader perspective on the diverse ways people have designed, built, and lived in cities over the ages. These are things I've discussed quite a bit in this blog. I go on to describe our transdisciplinary urban project at Arizona State University, and then discuss two topics: low-density tropical urbanism (the theme of the other 2 papers in the special section) and research on ancient urban sustainability (drawing on my paper, Smith 2010).

We were asked by UGEC Viewpoints to say something about the policy implications of research, so I give a few opinions on that matter. Briefly, planners and policy makers don't care about ancient cities, and they are not going to look at our archaeological findings to provide clues or guidance for contemporary urban issues. But enlightened planners and policy makers do care about research on cities and urbanism in general, and if archaeologists can provide data to broaden that more general body of research, then our results might have an indirect effect on policy or planning.

The second paper in the UGEC Viewpoints special section is: Scarborough, Vernon L., Arlen F. Chase and Diane Z. Chase  (2012)  Low-Density Urbanism, Sustainability, and IHOPE-Maya: Can the Past Provide More than History?
They talk about the project IHOPE-Maya, which involves a number of specialists in Maya archaeology and some formal modelers who are examining Classic Maya society in terms of concept or resilience and sustainability. This is an exciting endeavor. The Maya had fascinating cities and distinctive urban social and cultural expressions, but most fieldwork has been very particularistic. That is, archaeologists excavate Maya sites to learn about Maya sites, without much comparative analysis and without much concern with using their results to shed light on broader questions. The authors state,

"With respect to the ancient Maya, determining the degree to which they successfully altered their environs – or regionally damaged it – within the constraints of their technologies and innovations has great potential for assessing present-day societal adaptations." (p. 20)

This is an important new direction for Maya studies. I must admit that I find some of the article puzzling. I am not sure what the authors mean by this statement:

"Perhaps our Western technologies are now finally poised to revisit a notion of urbanism reclaimed from the past." (p.21)

They go on to make a comparison between Maya and modern urbanism that seems very abstract:

"the internet and the cultivation of market-driven co-operatives based in rural settings are the loose equivalent of the roads and calendars (the internet) and resource-specialized communities (the cooperatives) of the Maya."  (p.22)

Tikal, Guatemala, one of the largest of the Classic Maya cities

In the third paper, Christian Isendahl attacks the problem of "urban essentialism" ("Investigating Urban Experiences, Deconstructing Urban Essentialism"). Urban essentialism is one of the perspectives that holds back our understanding of general patterns of modern and ancient urbanism. Isendahl shows,

"how deep-rooted the modernist perception of urban essentialism has been over the last century, dominating and streamlining how we tend to think about urbanism as a largely uniform type of social formation, even in the pre-modern past."  (p.27)

In other words, many people--both the public and scholars--have this idea that there is a single kind of urbanism and a single kind of city, when in fact there is much variation around the world and through history. Isendahl focuses on the topic of urban agriculture, and how it goes against the standard western view that rural and urban and completely different and opposed settings:

"The body of evidence indicates that agricultural production cannot comfortably be regarded as ‘the antithesis of the city’ — as common essentialist-flavored understandings of urbanity seem to suggest — but is in many cases a fully integrated urban activity, viewed at the long-term and global scales." (p.28)

Above, I use the phrase "might be relevant" for the role of ancient cites in contributing to our knowledge of general patterns of urbanization today. Here is the problem. While archaeologists have lots of data on issues of cities and the environment, resilience, social patterns, and so on, we have yet to analyze those data in a framework that can be used by scholars working on contemporary urbanism. Right now, about all we can do is bring up some isolated examples. So while there are some urban scholars out there who think that past cities are relevant to contemporary concerns, archaeologists have yet to get our act together to produce reliable scientific findings that those scholars could use. This is the basic theme of Smith (2010). For a broader statement of the idea that archaeological can contribute to wider social-science research, see Smith et al. (2012).

For more discussion of these issues, look over my past posts, and check out some of these papers:

Barthel, Stephan and Christian Isendahl
2012    Urban Gardens, Agriculture, and Water Management: Sources of Resilience for Long-Term Food Security in Cities. Ecological Economics ( in press; published online).

Costanza, Robert, Sander van der Leeuw, Kathy Hibbard, Steve Aulenbach, Simon Brewer, Michael Burek, Sarah Cornell, Carole Crumley, John Dearing, Carl Folke, Lisa Graumlich, Michelle Hegmon, Scott Heckbert, Stephen T. Jackson, Ida Kubiszewski, Vernon Scarborough, Paul Sinclair, Sverker Sörlin and Will Steffen  (2012)  Developing an Integrated History and future of People on Earth (IHOPE). Current Opinion in Environmental Sustainability 4(1):106-114.

Isendahl, Christian  2012    Investigating Urban Experiences, Deconstructing Urban Essentialism. UGEC Viewpoints (Urbanization and Global Environmental Change) 8:25-28.

Isendahl, Christian and Michael E. Smith 2013    Sustainable Agrarian Urbanism: The Low-Density Cities of the Mayas and Aztecs. Cities 30 (in press; published online).

Scarborough, Vernon L., Arlen F. Chase and Diane Z. Chase  (2012)  Low-Density Urbanism, Sustainability, and IHOPE-Maya: Can the Past Provice More than History. UGEC Viewpoints (Urbanization and Global Environmental Change) 8:20-24.

Scarborough, Vernon L., Nicholas P. Dunning, Kenneth B. Tankersley, Christopher Carr, Eric Weaver, Liwy Grazioso, Brian Lane, John G. Jones, Palma Buttles, Fred Valdez and David L. Lentz  (2012)  Water and sustainable land use at the ancient tropical city of Tikal, Guatemala. Proceedings of the National Academy of Sciences 109:12408-12413.

Smith, Michael E.  2010    Sprawl, Squatters, and Sustainable Cities: Can Archaeological Data Shed Light on Modern Urban Issues? Cambridge Archaeological Journal 20:229-253.

2012    The Role of Ancient Cities in Research on Contemporary Urbanization. UGEC Viewpoints (Urbanization and Global Environmental Change) 8:15-19.

Smith, Michael E., Gary M. Feinman, Robert D. Drennan, Timothy Earle, and Ian Morris  2012    Archaeology as a Social Science. Proceedings of the National Academy of Sciences 109:7617-7621.

Modern use of an ancient farming system

Raised field construction (from Clark Erickson)

Raised fields -- an ancient form of agriculture, practiced by the Mayas, Aztecs, and the ancestors of the Incas -- was one of the most productive preindustrial farming systems anywhere. These fields were abandoned in most areas centuries ago, and largely forgotten. In the 1980s archaeologists excavated ancient raised  fields around Lake Titicaca in the Andes. Based on their findings, modern rural peoples started rebuilding raised fields. They turn out to be well adapted to the natural and social systems of the Titicaca area.

Archaeological interest in ancient raised fields starts with the observation that they were a form of
"intensive agriculture." Urban populations need large amounts of food, and with primitive transportation methods food had to be grown locally (unless we are talking about imperial Rome, where food could be shipped across the Mediterranean from Egypt easily and inexpensively). Under preindustrial conditions, "intensive agriculture" refers to methods that require considerable investment of labor in order to increase the yield on the land. Consider the difference between rainfall agriculture and irrigation agriculture in a given environment. The construction of canals and dams, and their required maintenence, can increase yields tremendously, but at the cost of requiring much more labor than rainfall agriculture. Irrigation is an example of intensive agriculture, while rainfall farming is a kind of extensive agriculture.

Figure 1 - Tiwanaku

Figure 2 - Relic fields on the shore of Lake Titicaca

Large, complex urban societies almost always rely on farming systems with intensive methods to feed their population. The most common forms of preindustrial intensive agriculture around the world were canal irrigation and hillside terracing. The earliest cities in Mesopotamia used irrigation, while the Inka cities of the Andes relied on terracing (with some irrigation). Aztec cities used both methods, plus the intensive cultivation of kitchen gardens. But perhaps the most remarkable form of ancient intensive agriculture were raised fields. This is a method of swamp reclamation, where long, parallel field beds are created by piling up dirt and muck from the swamp. Shallow canals are left in between the raised beds, and these canals have to be cleaned out periodically by scooping up the muck (a natural organic fertilizer) and piling it on the fields.

Fig. 3 - Clark Erickson

I talked about Aztec raised fields (called "chinampas") in a previous post. Here I want to focus on raised fields in the Andes. Tiwanaku was major urban center in Bolivia near Lake Titicaca, that flourished between AD 600 and 800 (fig 1). The plain around Lake Titicaca today is full of remnants of ancient raised fields (fig 2) that helped support the ancient city's population. A number of archaeologists have excavated and studied these ancient fields (see bibliography below). Here, I focus on the work of Clark Erickson (fig 3).

Fig 4

Clark Erickson (an old pal from graduate school at the University of Illinois) began with excavation and mapping of the fields, but then decided to see whether he could re-introduce the system for use by contemporary campesinos. In many ways ancient forms of intensive agriculture would seem to work well in the developing countries today -- they have high yields, use simple technology, they rely mainly on human labor, and they keep control of farming in local hands. This is a low-tech approach to economic development, using principles pioneered by EF Schumacher in his book, Small is Beautiful: Economics as if People Mattered (fig 4). It is the opposite of the high-tech approach that involves mechanized equipment, petrochemicals, and hybrid seeds. While many development agencies championed the latter approach, in fact it can be detrimental in poor rural areas. Once the foreign funding runs out, farmers can't buy or repair equipment, they can't afford the fertilizers and herbicides, and the result is that a few people get rich and most get poorer.

Fig 5 - Rebuilding ancient fields

Fig 6 - Ancient and rebuilt raised fields

Fig 7 - Building new fields

Clark managed to get some people to rebuilt and rehabilitate ancient raised fields (figs 5, 6), and others to build new fields from scratch (fig 7). He made use of a publicity campaign involving comic-book like pamphlets with text in both Spanish and Aymara (fig 8). At first the fields were a real success, and some farmers had yields higher than those who were following the high-tech development approach. Although his efforts were opposed by development experts from the United Nations and other development organizations, up to ten square km were planted in new raised fields in the 1980s.

By the 1990s, however, the results were mixed. Most of the farms that had been built communally, by large groups, had been abandoned. But the household-level farms, where individual families had built and farmed the new fields, were still functioning.

Fig 8 - Local publicity material

Clark Erickson has since moved on to pursue similar research in the swampy plains of eastern Bolivia, the Llanos de Mojos. He is just one of the archaeologists who have tried to re-introduce ancient farming systems to modern farmers. Alan Kolata has also worked on the Lake Titicaca raised fields, and Christian Isendahl is now working on ancient/modern connections with other indigenous farming systems in Bolivia. I tried doing something similar once in Mexico. An agronomist and I wanted to excavate Aztec terraces, study how they worked, and then try to get modern campesinos to rebuild the ancient terraces and use them again. We could not get funding for our project, however, and then we both ended up working on different topics.

The work of Clark Erickson and the other archaeologists mentioned above are great examples of how archaeological research on ancient cities is relevant to the concerns of the modern world. As we search for solutions to problems of hunger and poverty in the developing world, it behooves us to pay attention to ancient cities and cultures. Many of them were highly successful, and they have clues that can help us today.

• Check out Clark's homepage at the University of Pennsylvania. He has copies of these and other papers available to download:

Erickson, Clark L.
1989    Raised Field Agriculture in the Lake Titicaca Basin: Putting Ancient Agriculture Back to Work. Expedition 30 (3): 8-16.

1992    Applied Archaeology and Rural Development: Archaeology's Potential Contribution to the Future. Journal of the Steward Anthropological Society 20 (1-2): 1-16.

1992    Prehistoric Landscape Management in the Andean Highlands: Ridged Field Agriculture and Its Environmental Impact. Population and Environment 13: 285-300.

2003    Agricultural Landscapes as World Heritage: Raised Field Agriculture in Bolivia and Peru. In Managing Change: Sustainable Approaches to the Conservation of the Built Environment, edited by Jeanne-Marie Teutonica and Frank Matero, pp. 181-204. Getty Consserfation Institute, Los Angeles.

2006    Intensification, Political Economy, and the Farming Community: In Defense of a Bottom-Up Perspective on the Past. In Agricultural Strategies, edited by Joyce Marcus and Charles Stanish, pp. 334-363. Cotsen Institute of Archaeology, UCLA, Los Angeles.

Erickson, Clark L. and Kay L. Candler
1989    Raised Fields and Sustainable Agriculture in the Lake Titicaca Basin of Peru. In Fragile Lands of Latin America: Strategies for Sustainable Development, edited by John O. Browder, pp. 230-248. Westview Press, Boulder.

• For other relevant research, see:

Janusek, John W. and Alan Kolata
2004    Top-Down or Bottom-Up: Rural Settlement and Raised Field Agriculture in the Lake Titicaca Basin, Bolivia. Journal of Anthropological Archaeology 23: 404-430.

Kolata, Alan L.
1986    The Agricultural Foundations of the Tiwanaku State: A View from the Hhinterland. American Antiquity 51: 748-763.

Kolata, Alan L., O. Rivera, J. C. Ramírez, and E. Gemio
1996    Rehabilitating Raised-Field Agriculture in the Southern Lake Titicaca Basin of Bolivia. In Tiwanaku and its Hinterland: Archaeology and Paleoecology of an Andean Civilization. Volume 1, Agroecology, edited by Alan L. Kolata, pp. 203-230. Smithsonian Institution Press, Washington, DC.

But Aren't Modern Cities Very Different from Premodern Cities ?

This post is a kind of reply to my previous post, "Why are Premodern Cities Important Today?" If cities today are completely different from those that came before, then it is hard to make the argument that premodern cities have anything to tell us about urbanization today. I am playing devil's advocate with myself here. These are the main arguments I have found in the literature on how modern cities are very different from earlier cities. They come mostly from environmental historians.

(1) The Industrial Revolution

Environmental anthropologist Emilio Moran talks about how cities after 1800 (I assume he refers to  Europe and North America) differed greatly from earlier cities. He presents a common technological and demographic argument:

Prior to the eighteenth century, urbanization was a limited phenomenon and cities had a coupled relationship to their surrounding rural areas. Provisioning cities back then depended on a relatively proximate rural zone near the city. Cities recycled their ‘night soil’ and other urban wastes in the nearby rural areas, making them bad smelling but ecologically virtuous (Guillerme 1988; Harvey 1996). These same processes also made cities a locus of disease, pestilence, and plagues that decimated urban populations until the implementation of drainage systems, potable water supplies, and public health services. Before 1800 the ecological footprint of cities was light because they were embedded bioregionally and their size permitted provisioning by the immediate surrounding hinterland. (Moran 2008: 310).

(2) Cities and the Environment

(A)  Environmental historian John McNeill focuses on urban changes in the twentieth century:

Twentieth-century urbanization affected almost everything in human affairs and constituted a vast break with past centuries (McNeill 2000:281).

McNeill points to changes in the sizes of cities, the nature and extent of garbage and pollution, and the size of ecological footprints.

(B) In the broader sustainability literature, the great social changes of the recent period are sometimes referred to as the "Great Acceleration" and the epoch is sometimes referred to as "the Anthropocene" (Steffen et al 2007).

These and many other changes demonstrate a distinct increase in the rates of change in many human-environment interactions as a result of amplified human impact on the environment after World War II—a period that we term the “Great Acceleration. (Hibbard et al 2007).

For an up-to-date review of the environmental focus on contemporary urbanization, see Seto et al. (2010).

(3) The World Picture

For twentieth century changes in cities, urban scholars Gordon McGranahan and David Satterthwaite stress globalization and the expansion of the world capitalist economy over the strictly environmental factors discussed above:

The most important underpinning of urban change during the twentieth century was the large increase in the size of the global economy. In general, the nations with the largest cities and with the most rapid increase in their levels of urbanization are the nations with the largest increases in their economies. (McGranahan and Satterthwaite 2003: 246).

Unlike many urban scholars who rarely think beyond the modern western world, these two are clearly concerned with urbanization all over the world today (as their many fine publications indicate).

(4) An Archaeological Response

While not disagreeing with any of the observations listed above,  I think that there are still non-trivial continuities, similarities and parallels between modern and ancient cities. Indeed, this whole blog is based on this premise. But just how far can the similarities be pushed? We still need considerable comparative research to answer this question. Many of my posts in this blog illustrate my own exploration of this theme. But I am not the only archaeologist who feels this way. A number of years ago, Monica Smith (no relation!) made this observation:

Rather than seeing cities as fundamentally changed by the advent of the Industrial Revolution and the global connections of the modern world, new anthropological research suggests that both ancient and modern cities are the result of a limited range of configurations that structure human action in concentrated populations (Monica Smith 2003:2).

I heartily agree!! What do you think? I'd be interested in other opinions on this matter.

References:

Hibbard, Kathy A., Paul J. Crutzen, Eric F. Lambin, Diana M. Liverman, Nathan J. Mantua, John R. McNeill, Bruno Messerli, and Will Steffen

2007    Group Report: Dacadal-scale Interactions of Humans and the Environment. In Sustainability or Collapse? An Integrated History and Future of People on Earth, edited by Robert Costanza, Lisa J. Graumlich, and Will Steffen, pp. 341-375. MIT Press, Cambridge, MA.

McGranahan, Gordon and David Satterthwaite

2003    Urban Centers: An Assessment of Sustainability. Annual Review of Environment and Resources 28:243-274.

McNeill, John R.

2000    Something New Under the Sun: An Environmental History of the Twentieth-Century World. Norton, New York.

Moran, Emilio F.

2008    Human Adaptability: An Introduction to Ecological Anthropology. 3rd ed. Westview, Boulder.

Seto, Karen C., Roberto Sánchez-Rodríguez, and Michail Fragkias

2010    The New Geography of Contemporary Urbanization and the Environment. Annual Review of Environment and Resources 35:167-194.

Smith, Monica L.

2003    Introduction: The Social Construction of Ancient Cities. In The Social Construction of Ancient Cities, edited by Monica L. Smith, pp. 1-36. Smithsonian Institution Press, Washington, DC.

Steffen, Will, Paul J. Crutzen, and John R. McNeill

2007    The Anthropocene: Are Humans Now Overwhelming the Great Forces of Nature? Ambio 36:614-621.

Why are premodern cities important today?

Medieval street life

Sociology without history resembles a Hollywood set: great scenes, sometimes brilliantly painted, with nothing and nobody behind them. Seen only as the science of the present or — worse yet — of the timeless, sociology misses its vocation to fix causation in time. It thereby vitiates its vital influence on historical thinking, its influence as the study of social mechanisms operating continuously in specific times and places.

-- Charles Tilly (2008:120)

Substitute "urban studies" for sociology, and this quote from Charles Tilly nicely describes one of the reasons that premodern cities are important if we are to understanding cities and urbanism today, throughout history, and in the future. (I use the term "premodern" to include ancient cities around the world, European cities prior to the industrial revolution and world cities prior to the expansion of European imperialism).

I see at least four reasons for the continuing importance of premodern cities for understanding modern and more general processes of urbanization. Two are examples of what I call the "urban trajectory" argument: trajectories of urban change over the decades and even over centuries show us how cities work, and how they respond to and shape developments in their social contexts. The other two reasons are versions of the "sample size" argument: adding premodern cities to the list of modern cities gives us a much larger sample, which helps us in both understanding and planning/managing cities.

Kilwa (Swahili)

 1. Urban trajectory argument, A: the long perspective

The quote from Winston Churchill that I use in the description of this blog (see the right-hand column) justifies this argument: "The farther back we look, the farther ahead we can see." Archaeological data on ancient cities describe trajectories of urban expansion and retraction over long periods. Why were some cities successful for many centuries while others rose and fell within a decade or two? Why did cities initially develop in several parts of the world independently? Big urban questions like these can only be answered with the long time perspective of archaeology and history.

2. Urban trajectory argument, B: the short perspective

To understand the nature or structure of cities (or society) today, we need to know how they developed in recent decades and years. The urban past created the urban present, an argument Richard Harris has illustrated in several works (Harris and Lewis 1998; Harris and Smith 2011). Sometimes cities develop in ways that leave them little opportunity to easily change (this is called path dependence), and in other cases urban development is more flexible, allowing more options today and in the future. This second trajectory argument also applies in the past. Europeans constructed colonial cities in the New World, but those of Latin America differed from those in North America. Part of the reason for these differences is the existence of vibrant indigenous urban traditions in many parts of Latin America, but not in North America. Indigenous trajectories influenced subsequent urban development.

Babylon

3. Sample size argument A:  a broader base for generalization and explanation

Many observers are struck by regularities in city form and process. All cities have neighborhoods. Nearly all cities have a civic center with prominent public buildings. Many cities have higher population densities than smaller settlements in their society. To fully appreciate the patterns of similarity and difference among cities, scholars need to draw on as large a sample of cities as possible. Most works on urban history and comparative urbanism focus wholly on the western urban tradition, which obviously biases our picture of cities (and many other social phenomena). But cities in other eras may or may not have resembled European cities. Cities in pre-European Africa and in Mesoamerica were much more dispersed than western cities, yet they shared the same urban functions (administrative roles, economic activities, religious significance, etc.). We will never be able to understand the phenomenon of urbanism unless we consider the widest possible range of cities.

4. Sample size argument, B: more choices for planners and managers to draw on

Urban growth and its affects on society and the environment is surely one of the major social problems facing us today. How can we cope with persistent poverty, crime, and overcrowding in many cities? How can we reduce the ecological footprint or the carbon footprint of our growing cities to make them more environmentally sustainable? Planners, politicians, managers (and scholars) who consider these issues need ideas. If they consider a wider range of cities and urban traditions, they may be able to come up with better solutions to today's urban issues. I am not arguing that a detailed knowledge of, say, Teotihuacan, will by itself illuminate the problems of a city like Phoenix today. But if planners are familiar with Teotihuacan, Machu Picchu, Ur, Timbuktoo, Kilwa, and other premodern cities, this may help stimulate creative thinking on how we might improve cities today.

Teotenango, Mexico. The ancient ruins are on a cliff above the modern town

References

Harris, Richard and Robert Lewis
1998    How the Past Matters: North American Cities in the Twentieth Century. Journal of Urban Affairs 20:159-174.

Harris, Richard and Michael E. Smith
2011    The History in Urban Studies: A Comment. Journal of Urban Affairs 33(1):99-105.

Smith, Michael E.
2010    Sprawl, Squatters, and Sustainable Cities: Can Archaeological Data Shed Light on Modern Urban Issues? Cambridge Archaeological Journal 20:229-253.

Tilly, Charles
2008    Explaining Social Processes. Paradigm Publishers, Boulder, CO.