Long Trends—Rates of Innovation

Long Trends—Rates of Innovation

Lecture 34

One more example [of micro-innovations] may be the slow spread of windmills. We rst get evidence of them in Persia late in the 1st millennium C.E. And then they start to spread quite widely throughout the Mediterranean, eventually in Europe.

By modern standards, change was slow in the era of Agrarian civilizations. So it is all too easy to think of this as an era of stagnation. Yet we have also seen that there was considerable long-term growth in this period, and that suggests that there must have been a continuous trickle of innovations. What factors encouraged innovation in the era of Agrarian civilizations? Earlier lectures argued that collective learning—the ability to share and accumulate learned information—is what makes our species different. Ultimately, collective learning is the source of all innovation in human history. Indeed, collective learning can generate cycles of positive feedback, as innovations allow population growth, which increases the number of people contributing to innovation. But speci c features in each era and region can also accelerate or slow the pace of innovation. This lecture discusses four features of Agrarian civilizations that could stimulate innovation.

Population growth.

Expanding networks of exchange.

Increasing market activity.

The role of states.

Danish economist Ester Boserup (1910–1999) argued famously that population growth can stimulate innovation, as those at the edges of society are forced to seek new ways of feeding and supporting themselves. During the 4,000 years of the later Agrarian era, human populations multiplied by about ve times, growing from about 50 million to about 250 million people.

Feeding these growing populations depended on a constant trickle of miniinnovations, some of which were almost certainly driven by population pressure. Peasants or their masters sought out new lands to farm and encouraged settlement in new regions. That meant adapting to new soils, climates, and neighbors and adopting new farming techniques and crops. Examples include new crops such as the strains of rye that allowed farmers migrating from eastern Europe to begin settling the lands of modern Russia some 1,500 years ago, or the slow spread of windmills, which are rst recorded in Despite their hostility to Persia late in the 1st millennium C.E. commerce, tribute-taking The increasing size and variety of rulers could also stimulate exchange networks could also stimulate innovation and growth. the spread of innovations. Roughly speaking, the larger and more diverse the networks of exchange, the larger the pool of ideas they contained, and the greater the chances for the spread of signi cant innovations. In the later Agrarian era, the most important large exchange networks were the “silk roads,” which crossed most of the AfroEurasian world zone. As early as 4,000 years ago, innovations such as horse-riding and the use of chariots may have diffused from the steppelands to the Mediterranean region and also to China, while Indo-European languages, which probably originated in modern Russia, were spreading toward China, India, and Mesopotamia. Two thousand years ago, trans-Eurasian exchanges became more common. Chinese governments traded with Central Asia, Chinese silks entered Mediterranean markets, and Buddhism traveled from India to China. The travels of Chinese envoy Chang Ch’ien to Central Asia in the reign of Han Emperor Wu-ti (141–87 B.C.E.), or the astonishing military campaigns of Alexander the Great (365–323 B.C.E.), provide vivid illustrations of how Agrarian civilizations from different ends of the Eurasian landmass came into closer contact with each other. Sea trade also increased between the Mediterranean, India, Southeast Asia, and China, as mariners learned to exploit the monsoon winds of the Indian Ocean. By 2,000 years ago, and perhaps earlier, most of Afro-Eurasia belonged to a single “world system.” (The term “world system” is derived from the work of Immanuel Wallerstein

and refers to a large region linked within a single network of exchanges.) This meant that goods, ideas, religions, and technologies were now being exchanged across the largest of all the world zones.

The expansion of commerce and trade was also a crucial source of innovation. Since Adam Smith (1723–1790), economists have understood that competitive markets encourage innovation. Unlike tributary rulers, merchants lacked the power to generate wealth by force; instead, they had to use nesse. They had to produce and sell goods as ef ciently and cheaply as possible. That required a constant openness to innovation. This is “Smithian” growth. Tributary rulers normally despised commerce, but they also needed goods such as rare stones or silks, or horses that only merchants could supply, so they often protected commerce. But merchants ourished best in the cracks between Agrarian empires, such as in small city-states that traded with wealthy neighbors. Venice and Genoa in Renaissance Italy and ancient Phoenicia are good examples of such highly commercial citystates. Urbanization stimulated commerce because cities sucked in goods, techniques, and people from large hinterlands. In 3000 B.C.E., few cities had more than 30,000 inhabitants, and most were in Mesopotamia or Egypt. By 100 C.E., there may have been over 70 large cities spread throughout AfroEurasia, some with populations of several hundred thousand (Christian, Maps of Time, p. 326).

Despite their hostility to commerce, tribute-taking rulers could also stimulate innovation and growth. Generally, tribute-takers had less incentive to innovate than merchants, because they could extract resources coercively. Indeed, in an era when growth was painfully slow by modern standards, it often made more sense to capture wealth through war, than to produce wealth through investments that could take generations to mature. That is why most rulers in the later Agrarian era thought of themselves primarily as warriors rather than producers. They admired warfare, found ful llment in it, and spent much time preparing for it. Nevertheless, to succeed as tributary rulers, they sometimes had to encourage innovation. Heavy taxation encouraged innovation, as peasants were forced to raise production in order to feed themselves and pay taxes. The most farsighted rulers understood that they could increase tributes by stimulating production and maintaining infrastructure. That meant protecting peasants, building and maintaining

irrigation systems, and avoiding excessive taxation. Military and strategic factors encouraged rulers to undertake large projects that often encouraged trade and commerce. In the Roman Empire, military needs stimulated innovation in road building, bridge building, the construction of aqueducts, and the building of elaborate military catapults and siege engines. Such innovations had signi cant “trickle-down” effects. Joel Mokyr writes, “The Rome of 100 A.D. had better paved streets, sewage disposal, water supply, and re protection than the capitals of civilized Europe in 1800” (Christian, Maps of Time, p. 321). The building of monuments such as the pyramids could also provide employment and encourage innovation in areas such as architecture, engineering, and mathematics.

We have seen that there were several features of Agrarian civilizations that tended to encourage innovation and growth. Yet we also know that in this era, innovation was much slower than in the Modern era. Why? There must have been other factors that retarded innovation and growth, and indeed there were. We will describe some of them in the next lecture.

Essential Reading

Supplementary Reading

Bentley and Ziegler, Traditions and Encounters, chap. 12. Christian, Maps of Time, chap. 10. Fernandez-Armesto, The World, chaps. 7, 8.

Brown, Big History, chaps. 7, 8. Chase-Dunn and Hall, Rise and Demise. Mokyr, The Lever of Riches, Introduction, chap. 1.

Questions to Consider

1. What evidence is there that signi cant innovation occurred during the era of Agrarian civilizations?

2. What were the main forces that stimulated innovation in the era of

Agrarian civilizations?