For decades, Li Bozhong has argued that understanding China’s long-term economic development begins with Jiangnan — the fertile delta south of the Yangtze River, where preindustrial China achieved a level of productivity rivaling Europe’s.

Now 76 and chair professor of humanities at Peking University, Li has spent his career combining exhaustive archival research with an instinct for how technology, labor, and land shaped China’s economy.

The son of historian Li Yan, he was among the first scholars to earn a doctorate after the founding of the People’s Republic of China, a path that set him on a lifelong study of China’s economic past. His interdisciplinary method and command of primary sources have produced a body of work that reshaped the understanding of China’s economic history.

That approach culminated in his benchmark study, “Early Industrialization in Jiangnan, 1550–1850,” which shows that in handicraft output, labor organization, and commercial activity, Ming-Qing period (1368–1911) Jiangnan rivaled the contemporary Netherlands. The finding directly challenges the “Great Divergence” thesis, which argues that Europe surged ahead of China between the 17th and 19th centuries.

Unlike most economic historians who focus on “relations of production,” Li centers on “productive forces,” the technologies, resources, and labor practices that drove growth.

His research has shown how Qing-era Jiangnan farmers developed elaborate systems for collecting and processing human waste, turning night soil into fertilizer that sustained the region’s exceptional yields. He has also documented how widespread practices of abortion, contraception, and sterilization in the eastern Jiangsu and Zhejiang provinces reveal a tradition of fertility control that predated Malthus by centuries.

In recent years, Li has turned from Jiangnan to the wider patterns linking China with the early global economy. Later works such as “Theories, Methods and Trends of Disciplinary Development” and “Guns and Ledgers: China and the East Asian World in the Age of Early Economic Globalization” extend his empirical rigor to East Asia’s regional and global trade networks.

Speaking at this week’s Second World Conference on China Studies in Shanghai, Li explored these themes in a keynote on “Trade: The Most Important Way of Historical Exchange Between China and the World,” before sitting down with Sixth Tone for a conversation on commerce and connection.

Sixth Tone: Professor Li, your keynote speech explored China’s commercial history. Could you outline the main trajectory of China’s trade with the outside world? Is the Han-era (206 BC–AD 220) Silk Road really the place to begin?

Li: The Silk Road is famous, and rightly so. Stretching across Eurasia, it linked the great civilizations of China, Persia, India, Central Asia, and the Mediterranean, and its symbolic role in early Sino-foreign exchange is undeniable. Yet from an economic standpoint, its significance should not be overstated.

Consider the terrain: towering mountains, deserts, and steppes, much of it uninhabited. Every journey faced bandits, blizzards, and thirst. After the third century CE, banditry became endemic; robbery and murder were common, and whenever security broke down, trade dwindled. The Silk Road’s history of repeated openings and closures reflects just how fragile it was as a commercial channel.

Sustained, large-scale trade between China and the wider world began much later, during the Southern dynasties (420–589), and not by land through Central Asia but by sea — along what we now call the Maritime Silk Road.

This network linked the East and South China Seas, the Malacca Strait, and the Indian Ocean. By the late Tang (618–907) period, Guangzhou already hosted large amounts of foreign immigrants. An Arab chronicler wrote that when Huang Chao sacked the city in 878, some 120,000-200,000 Muslim, Jewish, Christian, and Zoroastrian merchants were killed. While this figure is likely exaggerated, it points to the presence of a substantial foreign merchant community.

Under the Song dynasty (960–1279), maritime trade flourished as never before, powered by several major Chinese innovations: the watertight bulkhead, the magnetic compass, and great progress in shipbuilding. These reduced shipping risks, increased cargo capacity, and pushed seaborne commerce past a critical threshold. By the Yuan dynasty (1279–1368), Quanzhou had overtaken Guangzhou as China’s leading port — a prosperity vividly described in travelers’ accounts from the time.

Sixth Tone: What, then, was flowing in and out of China during this commercial boom, and who was moving it?

Li: China’s main exports were silks, with porcelains gradually taking the lead. By the Tang dynasty, Persia had already mastered sericulture, but porcelain remained a Chinese monopoly for centuries. Recent underwater excavations along the maritime routes confirm this pattern.

Imports moved in the opposite direction. Spices from the tropical areas — peppers, cloves, nutmeg, cardamom, frankincense — were most sought after, followed in smaller quantities by gold, pearls, and tortoiseshell.

Up to the Ming dynasty (1368–1644), these exchanges were largely handled by fanke — sojourning merchants from the western Indian Ocean: Arabs, Persians, Indians, Jews, and others. In Quanzhou, for example, the Pu Shougeng clan, of Arab origin, served as superintendents of maritime trade under both the Song and Yuan. They owned entire fleets; Pu’s Persian son-in-law, Folián, is said to have commanded 80 oceangoing junks.

Chinese merchants, however, were never entirely absent. Despite Yuan statutes that reserved overseas commerce for semu — “auxiliary” peoples — figures such as Wang Dayuan still made repeated voyages into the Indian Ocean and the Mediterranean. His book “Brief Survey of the Islands” records journeys reaching as far as the East African coast.

Sixth Tone: You just noted that foreigners more or less monopolized China’s sea trade before the Ming. Did that change once the Ming began?

Li: Precisely, from the Ming onward, Chinese merchants gradually regained control of the country’s maritime trade. More importantly, from the mid-Ming period, both China’s main trading partner and its key import changed. The first catalyst was Japan’s rise.

By the early 17th century, Japan had become the world’s third most populous country and had discovered vast silver deposits. Its export capacity and domestic demand expanded in tandem. As a result, Japan emerged as China’s single most important trading counterpart. Raw silk sailed west across the East China Sea, while silver — valued not just as currency but as a commodity — flowed back in exchange.

The profits from this Sino-Japanese exchange were so large that they helped spark the wokou raids along China’s coast, prompting the Ming court to impose its “maritime prohibition” (haijin). Yet bans are one thing, business another. The Portuguese quickly spotted the arbitrage opportunity and stepped in as intermediaries, keeping the lucrative trade alive.

More importantly, there was the emergence of silver from the Americas. Spanish-ruled territories — notably Bolivia, Peru, and Mexico — held the world’s largest deposits. Under harsh colonial rule, these regions produced about 80% of global silver output. The Potosí mine in Bolivia alone yielded roughly 25,000 metric tons during the 17th and 18th centuries.

Silver became the main currency of early modern global trade. It was shipped first to Europe, then on to Asia, where Europeans used it to purchase Asian goods. At the time, China was one of the world’s leading trading nations. Western merchants came to buy Chinese products in massive quantities, bringing a corresponding inflow of silver into the country. According to the economic historian André Gunder Frank, of the roughly 120,000 metric tons of silver produced worldwide in the 17th and 18th centuries, about half ended up in China.

Therefore, silver soon replaced spices as China’s dominant import.

Sixth Tone: In the popular imagination, Ming China’s global outreach is symbolized by Zheng He’s “Western Ocean” expeditions — often seen as the height of the tribute system. Yet some scholars, including Kenneth Pomeranz and Steven Topik, argue that these state voyages also carried a genuine commercial logic. How do you see it?

Li: I’m not convinced. Zheng He’s expeditions were, at their core, political and diplomatic spectacles rather than profit-seeking ventures. Trade, by definition, seeks margins; the tribute system, in contrast, followed the principle of “giving more and receiving less.”

That said, Pomeranz and Topik raise valid points. They argue that imperial gifts were carefully priced in Chinese units of account, and tributary rulers were expected to adopt that standard. In doing so, Chinese monetary norms spread across East and Southeast Asia, creating a shared financial language. So while the voyages were not commercial in intent, their protocols inadvertently laid the groundwork for a regional monetary system.

Sixth Tone: Your work has long focused on Jiangnan’s economy and social structure. Could you give an example of how the region was linked to the early modern world economy?

Li: Take cotton cloth. From the late 18th century, China began exporting large quantities of cotton cloth to the West, in particular Britain and America. It was a little odd since China itself produced relatively little raw cotton. With so many mouths to feed, dedicating large tracts of land to the crop would have threatened grain supplies.

Yet Jiangnan’s yarn-dyed fabrics were so fine that British merchants were willing to absorb the extra costs. They took raw cotton in India, shipped it to Jiangnan, and had local weavers turn it into finished piece goods. See the global market and worldwide division of labor?

Sixth Tone: That does sound counterintuitive. If raw cotton was scarce in China, how did Jiangnan acquire the skills to dominate this niche?

Li: It speaks to the very character of Jiangnan, something I’ve spent a lifetime studying. Any lasting achievement depends on diligence, learning, and business acumen — qualities the region possessed in abundance.

Girls there began spinning at 5 years old, took up the loom at 7 or 8, and by 10 had already mastered years of continuous practice. Equally crucial was a sharp market sense. Families wove not just for their own use but for sale.

By the late Ming, professional cloth merchants had emerged. They advanced raw cotton of yarn or cash to spinner or weaver households, set delivery dates, and imposed strict quality checks; finished bolts that passed inspection were stamped with the firm’s trademark. One Suzhou house, selling several hundred bolts a year, operated under the same brand for two centuries.

Sixth Tone: So the story still circles back to trade.

Li: Precisely. The Chinese word for commerce, shang, comes from roots meaning “to consult,” “to deliberate,” and “to bargain” — and that is no accident.

A peasant can farm alone, and an artisan can craft alone. But the moment a product becomes a commodity — as with Jiangnan cotton — buyer and seller must engage in dialogue: about quantity, quality, price, and delivery. Only when both sides reach an agreement does the transaction take shape.

Trade, thus, is the most egalitarian form of human exchange. Throughout history, it has been the main channel through which different parts of the world have maintained continuous — and peaceful — contact.

Sixth Tone: Yet today, the term “trade war” dominates the headlines. How do you view this situation?

Li: Achieving genuinely equitable trade is a long historical process. Since the WTO’s founding, the international community has moved — unevenly but unmistakably — toward that goal. Yet there will always be actors who try to break from the rules they once accepted. The Trump administration’s use of punitive tariffs is, in my view, such a defection.

Over the long arc of history, rule-breaking never lasts. Those who undermine a multilateral order eventually find themselves bound by the very norms they sought to fracture.

Editor: Apurva.

(Header image: A Qing dynasty woodblock painting titled “All Walks of Life,” circa 1734. From Umi-Mori Art Museum)