Efficiency vs. Resilience: Global Supply Chain Collapse – Part 3: (Pre)Historical Trade

People have created large, complex cities and societies without fossil fuels in history and prehistory. In only one case that I know of did they depend on the shipment of staple foods and goods — and that was precarious. Traders did regularly move light-weight, valuable, robust goods over long distances, but a collapse in that supply chain was not life threatening. We’re going to look at three ancient societies and how they handled their supply chains for lessons we can use today: Romans, Mayas, and Incas.

At LTI we tend to look to the past for solutions we can adapt to a future without fossil fuels. In addition to natural systems, we look to successful (and failed) attempts to maintain large, complex societies (often called “civilizations” outside of academia) and what made the tick (or not).

Much of what I am writing here is adapted from one of my books, Why Did Ancient Civilizations Fail?. The premise is that societies often become overconfident in their ability to survive and thus stop adapting to changes in their surroundings. When they do this, they collapse. I focus on five interrelated components supporting societies: environment, agriculture, social systems, trade, and resilience to disasters, with ancient case studies for each. I hope to record this as an audiobook this winter. Writing this book was the inspiration to found this institute.

In Part 1, we looked at the underlying problem with “Just in Time” (JIT) and “Just in Case” (JIC) supply, and Part 2 examined natural systems. If you haven’t read them, head back and start there.

Rome: Dependent on Long-Distance Staples

Rome has been the archetypal ancient civilization for European-based scholars for millennia and for good reason. This empire ruled over a vast network of land and sea routes stretching from Britain to Arabia. Within the Pax Romana (Roman Peace), traders moved huge amounts of goods without fear of (too much) banditry. This reduced friction of movement led to profit and changes in the distribution of production.

As trade within the empire expanded, so to did the proliferation of luxury goods. Providing wine for Rome’s elite, for example, was more lucrative than wheat farming. Many estates in the heartland of the Empire, then converted from fields to vinyards in order to increase their profits. Wheat, after all, was available for cheap prices imported from province, especially Egypt.

Rome, and all ancient societies, had two ways to transport goods: over land or water. Land was slow and expensive, even on Roman roads. In 301 CE, for example, Diocletian’s price edict was implemented to fix prices and stop runaway inflation from too much adulterated currency. It decreed the cost of wheat transported by cart could only increase by 50 percent for every hundred miles traveled. By ship, the same distance only added 2 percent to the price. The inherent ease of water travel and its large payloads decreased its cost to the consumer.

When Rome conquered Egypt, about 30 BCE, it acted as a colonial power, eventually extracting goods back to the imperial capital. In this case, it was tons of wheat — Flavius Josephus, a Roman historian, cited four hundred thousand tons per year. Three decades earlier, pirates disrupted the Egyptian grain shipments, causing panic and skyrocketing bread prices in Rome. Pompey, the Roman general and later political leader, was dispatched to quell the pirates but even before he left, prices had dropped to record lows, suggesting local hoarding was the cause of the price spike. When Augustus Caesar later annexed Egypt, it was an attempt to stabilize grain shipments. Rome’s emperors may have used state resources to influence grain prices because the collective noun of “hungry citizens” is “pitchfork-and-torch-wielding mob.” The populous considered the government responsible for ensuring an adequate grain supply.

Maya: Long-Distance Trade in “Elite Treats”

The Maya, like many ancient societies, traded in three networks: local, long-distance, and tribute. As a general rule, utilitarian (“everyday”) commodities were produced and traded regionally and prestige goods were traded over long distances. Local trade largely consisted of staple foods, gathered resources, and common handicrafts, such as fabric and pottery. Peasant farmers were able to produce practically all of their vital resources locally but would trade for imported prestige items to raise their social status, just as you might seek out the newest iPhone for the social cachet of being on the cutting edge. Long-distance trade networks ideally moved items with high social value and low weight, such as quetzal feathers, jade, obsidian, salt, copal (ritual incense), and cacao. The elites’ social positions may have been more dependent on trade, as the goods needed to demonstrate their social status were often imports. Tribute linked these two networks together: commoners supplied the elites with local products and handicrafts, some of which would then be traded abroad for imported prestige goods (or used to support elite artisans who created exchangeable goods).

During what is commonly referred to as the “Maya Collapse” what we really see is a reorganization of the elite stratum of society and their trade network. Peasants, which made up 90 percent of the population, continued to survive, growing their own food and trading locally. We are often dazzled by the large buildings and shiny objects, but for the majority of people, the so-called collapse was the fall of religious and cultural elites and the rise of merchant empires.

What all this means is that only things not essential for everyday survival were traded over long distances. Certainly drought and famine were known in Maya history, but it is largely thought to be the result of drought and other environmental factors, not trade disruption. Indeed, across Mesoamerica, halt of traders was a cause of war, and traders were supposed to be able to pass into hostile territory unmolested. And although coastal and river transport were used, large ships could not pass the shallow waters, limiting the transport of heavy, bulky staples.

Incas: Diversity and Interconnection as Strength

At intervals ranging from two to eleven years, the El Niño Southern Oscillation (ENSO) disrupts the usual weather patterns on the west coast of South America. The erratic interval made it difficult to predict for preindustrial states in the Andes, and they were constantly planning for one to three years of agricultural and fishery disruption every decade.

Tampu storehouse (Smithsonian)

Inca agriculture was intimately tied with kin-based social networks to provide a variety of foods. The rapid changes in elevation of the Andes created closely spaced but varied growing environments. Fish and shellfish were caught in the sea. Maize, squash, cucumber, cotton, and fruits were grown near the coast. Coca, peppers, avocado, and more fruits could be farmed in the foothills. The most productive farmland was in the lower Andes, where maize (introduced from Mesoamerica after 2000 BCE), beans, vegetables, quinoa, peanuts, and tubers were grown. Thousands of varieties of potatoes and quinoa were farmed in the higher mountains and llamas and alpacas were herded in the highest elevations (guinea pigs were also kept for food everywhere). Warm-weather crops were grown on the eastern slopes, because of the proximity to the Amazon basin. Kin from different ecological zones shared their products amongst themselves in a system referred to as a “vertical archipelago” (Murra 1972).

Not only did this archipelago strategy provide the members of the network with a greater diversity of food than was available in their immediate environment, it helped spread the risk associated with ENSO-related climate disturbances (prompting Baudin [1961] to call it an early socialist empire). The farmers intercropped their plants, not only to maximize the small amount of arable land, but also to ensure that at least one crop would grow, regardless of the weather that year. Farmers further reduced the risk to their crops by scattering their fields and planting crops in series, spread out over the calendar. They also brought more land under cultivation by building extensive, state-organized terraces and complex irrigation systems.

The Inca maintained a road system of over 40,000 km (25,000 mi.), about the circumference of the Earth, which facilitated public and private commerce. It had two main north-south arteries, one in the highlands and one in the lowlands, with many perpendicular trunk roads. The road system facilitated the movement of llama-borne trade and the military. Every 20 km (12 mi.) or so, a roadside storehouse, or tampu, provided shelter and food for travelers, especially those on state business. Although the Inca had a beast of burden, the llama had nothing on a donkey, horse, or its cousin, the camel: it could only carry 30 kg (66 lb.) over 20 km (12 mi.) per day for three days before needing a day off. Human porters were faster and stronger. The empire had official relay messengers, or chaski, stationed every 6–9 km (4–6 mi.) along the main roads. This system could carry messages (or even fish) from the coast to Cuzco at a rate of 240 km (150 mi.) per day; faster than any horse over this terrain. Unlike the other areas, though, ship transportation was not a significant mover of goods, encouraging more local staple use.

Lessons for Today: Local Self-sufficiency

We can take our cue from these three ancient societies: local staples are stable staples. The Romans relied on imported grain and suffered when trade was disrupted. The everyday Maya did better with local staples, while the elites relied on prestige goods traded from afar for social position. And the Inca had the most resilient system with an intense network of shared resources and a state-organized reserve.

Our current economy is set up like the Roman Empire: the economic centers are specialized and produce finished products, relying on the import of staples from far away. Listen to a lecture I gave on the fossil-fuel intensity necessary for us to get many of our staples. This is fine if transportation is cheap, which it is right now. Like the Romans using ships over oxcarts, we use fossil fuels to hypercharge our transit network. Without these energy sources, however, our system grinds to a halt. Our just-in-time economy is only possible with a smoothly functioning transportation system, as discussed in part 1.

As we look to a future that is more resilient, we should take a hard look at the Inca economy — although it isn’t as efficient, it holds up to the stress of unpredictability. Because the El Niño occurs so often and without warning, they had to plan for the worst and hope for the best.

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