David Boyce and Huw Williams are both esteemed transportation scholars, each with their distinct areas of expertise. With their long and distinguished careers closely intertwined with the development of travel forecasting as an intellectual discipline, it is only fitting that they have chosen to write a book about its past, present and future.

I know Professor Boyce well. My master’s advisor, Professor Der-Horng Lee at the National University of Singapore, studied under Boyce while pursuing his Ph.D. at the University of Illinois at Chicago. Lee’s own master’s advisor, Huey-Kuo Chen from Taiwan’s Central University, was also one of Boyce’s doctoral students during his tenure at the University of Illinois at Urbana-Champaign. This means I am either Boyce’s academic grandchild, or great grandchild, depending on how you count. Thanks to Lee I was well aware of this academic lineage even before I came to the U.S. in the early 2000s. When I joined Northwestern University as an Assistant Professor in 2006, Boyce was serving his alma mater by teaching transportation system courses as an adjunct professor. It took me a while to process the surreal news that I would now be a colleague of my academic forebear.

During my first meeting with Boyce in Evanston, IL, I learned about his joint book project with Williams, which had already been in progress for several years. The book was an ambitious and intriguing endeavor aimed at reflecting on the achievements, missteps, and challenges in our field. It was finally published in 2015, nearly 12 years after they began the project. Shortly afterward, I was asked to oversee the translation of the book into Chinese, a project that would take another five years. Through this process, I had to read the book cover to cover — and between the lines — several times, ensuring I understood every word and phrase. It was a time-consuming and occasionally frustrating task, to be sure, but a rewarding learning experience nonetheless. Ultimately, it is this rare opportunity that inspired me to share in this essay what I learned from the book and the insights it brought to light.

You may find a preprint of the paper at ssrn. Also check the following podcast automatically generated by Notebook LM  based on a PDF of the paper I fed to it.

I was attracted to A Culture of Growth because I heard the book provides answers to the Needham question (李约瑟难题), namely why China, despite its early and significant achievements in technology, fell so far behind the West during the critical developmental phases of modern science.  Until I opened the book, I didn’t realize it was written by a Northwestern economist, Joel Mokyr, whom a friend in the economics department described as a leading authority on economic history.

Although Mokyr addresses the Needham question extensively in the final chapter, the book is neither motivated by nor primarily focused on that question.  Quite the contrary—if you read the book closely, you can’t miss Mokyr’s dismissal of the question itself. To him, what begs the question isn’t why China—or any other civilization, for that matter—failed to invent modern science, but rather why Europe succeeded. The book is devoted to providing an explanation.

Mokyr’s theory builds on Cardwell’s Law, which states that technological innovation tends to slow down or stagnate once an organization, economy, or civilization reaches a peak accomplishment. The stagnation occurs because the beneficiaries of the status quo become complacent and resist major creative disruptions that could threaten their dominance. Crucially, they often have the power to “suppress further challenges to entrenched knowledge” by either incentivizing would-be challengers to do their biddings or persecuting them as heretics.

How did Europe manage to break the spell of Cardwell’s Law? Mokyr attributed this success to Europe’s “fortunate condition that combined political fragmentation with cultural unity.” This unique environment gave rise to what he called a “Republic of Letters,” a loosely connected federation where intellectuals could freely exchange, contest, refine, and publish ideas across the borders of competing polities. This republic, along with the “market of ideas” it nurtured, rose gradually after the Middle Ages.

Europeans, following Bacon, began to recognize that knowledge could and should be harnessed for society’s material benefit, and that its creation, dissemination, and utilization should be a collective effort.  That is not to say the Republic of Letters was brought about by any concerted effort. Often motivated by the pursuit of lucrative patronage positions, the founding members of the republic sought to build strong reputations among their peers. This motive, in turn, pushed them to support free access to knowledge and uphold the right to challenge any idea, regardless of its origin.

The republic had no inherent hierarchy, except for the one that naturally emerged through fierce but largely free competition for peer recognition, based on a shared understanding of what constitutes merit.   Scholars who rose to the top of the pecking order often did fabulously well for themselves, attracting a “disproportionate amount of fame and patronage.”   They also became recruitment tools for the Republic of Letters and role models for future generations.  Newton was one such superstar whose influence as a model scientist is hard to overstate.  Mokyr wrote of Newton,

he was knighted, elected to Parliament, and became quite wealthy. In 1727 he was given a splendid funeral and interned in a prominent place in Westminster Abbey. Voltaire remarked that he was buried like a well-loved king.

Once the market of ideas took shape, it was sustained by Europe’s favorable geopolitical conditions.   On the one hand, political fragmentation meant that neither scholars nor their patrons could easily monopolize the market of ideas by blocking the entry of potential competitors or buying them off. Incumbents quickly realized that such maneuvers only pushed innovation into the hands of their rivals, ultimately undermining their own competitive advantage.   On the other hand, cultural unity allowed knowledge production and dissemination to benefit from scale. From an economic perspective, scale reduces the fixed costs of production, which is key to profitability and financial viability. It also created a network effect, meaning that scientists could learn from a relatively large pool of peers—standing on the shoulders of many giants, as Newton famously put it.

Mokyr’s “culture of growth” matured during the Enlightenment, an intellectual and cultural movement that promoted the progressive improvement of society through the expansion and application of useful knowledge, while advocating for more inclusive political institutions. In hindsight, it was clear why the Enlightenment played such a pivotal role in Mokyr’s theorization: it was the precursor to the Industrial Revolution, which triggered an unprecedented phase of economic growth that lifted much of humanity above subsistence living standards.

An interesting aspect of Mokyr’s theory is its focus on what he calls cultural entrepreneurs—or thought leaders, in today’s parlance—who played an outsized role in the evolution of the culture of growth. Mokyr believed that useful knowledge was created by “a minute percentage of the population” whose primary occupation is, in Adam Smith’s words, “to think and or to reason” for “the vast multitudes that labour.”  In fact,

 what the large majority of workers and peasants knew or believed mattered little as long as there were enough of them to do what they were told by those who knew more.

While Mokyr’s assessment is supported by historical evidence, I imagine many would find such an unapologetically elitist view of cultural development difficult to accept. For me, it feels almost antithetical: growing up in China, my history and political science teachers repeatedly taught, with absolute certainty, that it was proletariats who, through class struggle, drove societal progress and historical development.

Mokyr’s theory can explain why China experienced a burst of intellectual development during the Spring and Autumn and Warring States periods (770 – 221 BCE).  There are striking similarities between the geopolitical conditions of China in this classical era and those of Europe after the High Middle Ages: numerous relatively small states engaged in intense and perpetual competition for dominance, a vast territory with diverse terrain, and a shared cultural tradition including language, institutions, and faith.  Many cultural entrepreneurs—collectively known as “Hundred Schools of Thought”—emerged at this time and left indelible marks on the Chinese Literary Canon.  Like their European counterparts nearly two millennia later, these intellectuals built their reputations by creating and sharing knowledge, and when opportunities arose, they happily crossed the borders of rivalry states to seek more profitable employment for their skills.

As mentioned earlier, in Europe, the greatest achievement of the market of ideas was the Enlightenment. In China, however, a similar market of ideas culminated in a political philosophy that blended Confucianism and Legalism—what I shall refer to as “Confuleg” for lack of a better term (in Chinese, 儒法, or more precisely儒表法里).

Confuleg went on to become the political philosophy that underpinned the key institutions of the Qin-Han Empire, the first to truly unify what is now China under a powerful and centralized state. In the ancient world, this was a towering achievement—socially, politically, and economically. In fact, the state model based on Confuleg was so successful that one could argue, to some extent, China still operates in its long shadow even today.  However, Confuleg’s ascent to hegemony in China was effectively a death sentence for the market of idea.

Since the Qin-Han empire, China has seen dynastic succession once a few hundred years, each usually accompanied by an extended period of turmoil, violence and destruction.

When China is ruled by a centralized state, the Republic of Letters cannot survive, as Mokry’s theory predicts.  Since the best employment opportunity for intellectuals could only be found in the state’s bureaucratic system, producing new knowledge or earning a reputation among peers no longer promises financial security.  Instead, survival requires pledging allegiance to the state (i.e., the emperor himself), internalizing the principles of Confleg as one’s own beliefs and values, and excelling the exams designed to test the ability to memorize and interpret classical texts.   More importantly, the state does not tolerate any competition with its monopoly over ideas.  Questioning the state-sanctioned ideology is viewed not only as heresy but as an act of treason, often carrying the gravest of consequences.

When the centralized state collapsed, one might expect that the ensuing chaos and factional warfare would create an environment favorable for a thriving market of ideas. After all, isn’t that exactly what happened during the Warring States period? Not quite.    The Chinese Canon maintained its powerful grip on intellectuals through these turbulent times. It even survived the brutal and repressive Mongol rule, which lasted nearly a century.  Why?

David Hume (1711 – 1776) observed that few Chinese after the classical period had courage to “dispute what had been universally received by their ancestors.”  John Stewart Mill (1806 – 1873) echoed this view, noting that Chinese tended to “govern their thoughts and conduct by the same maxims and rules,” and as a result (emphasis mine),

they have become stationary—have remained so for thousands of years; and if they are ever to be farther improved, it must be by foreigners.

Today, these words may sound condescending, if not outright discriminatory. However, I often wonder what China might be like today had Westerners never forced their way in. Would it still more or less resemble the world under the reign of Emperor Qianlong in the late 1700s?

Beyond conformity to the same maxims, most Chinese thinkers shared a peculiar, pessimistic nostalgia for a world once ideal and perfect but irretrievably lost. Mokyr identified this trait among the Neo-Confucians—the followers of Cheng Hao, Zhu Xi and Wang Yangming—who dominated the intellectual world during the Ming dynasty.  These scholars regarded antiquity, Mokyr wrote, as “the ideal period, followed by a decline, with no guarantee that the world would ever be better.”   However, the mindset did not originate form Neo-Confucians; it can be traced back to Confucius himself, who lamented the disintegration of the Western Zhou institutions he regarded as ideal, writing

Zhou observed the two preceding dynasties, flourishing with culture and refinement! I follow the Zhou. (周监于二代，郁郁乎文哉！吾从周)

It is hardly surprising that such an inherently backward-looking worldview would become an obstacle to new ideas.

What does Mokyr’s theory suggest about the future of innovation in human society?

The Republic of Letters that once thrived in pre-industrial Europe has long since disappeared, replaced by a vast scientific enterprise supported by a plethora of public and private institutions. However, some key principles from the old republic remain.

First, freedom of expression is still a foundational value. In universities, this is institutionalized through tenure, ensuring that professors’ livelihoods are protected from those who dislike their ideas. Second, a scholar’s value continues to be largely determined by their reputation among peers. This is why peer review, whether for publications or grants, remains the gold standard in academia, despite frequent criticisms of inefficiency, inconsistency, and unfairness.

The value of the science enterprise as an indispensable pillar of modern soceity is almost universally recognized today. Thanks to globalization, science has truly become a global affair: ideas, money, and scholars can now move freely across borders.   This all sounds uplifting until you realize where innovations are first made and adopted still matters a lot.  As Chris Miller explained in Chip War, leadership in science and technology has been the cornerstone of America’s national security strategy.   Until recently, the open science enterprise has served this strategy pretty well.

From pioneering semiconductors to exploring space, from mapping the human genome to advancing artificial general intelligence, the U.S. has consistently led the way. While much of this success can be attributed to America’s global hegemony, her strong commitment to the core values of liberal democracy—free speech, property rights, and limited government—must have also played a crucial role, according to Mokyr’s theory.

The meteoric rise of China apparently has shaken America’s faith in open science.  Reasonable people can disagree on the nature of the current Chinese regime; but few can claim with a straight face that Chinese citizens enjoy much political freedom, as the term is usually understood in the West.  The Chinese do not elect their leaders through open and free elections; their speech is tightly monitored and censored; and they are largely ruled by law, rather than being protected by the rule of law.  In theory, such an environment should be hostile to the market of ideas, hence innovations.

Yet, China has made remarkable strides in science and technology since the turn of the century. By 2025, China is projected to produce nearly twice as many STEM PhD graduates annually as the U.S.  In 2022, Nature, one of the most prestigious scientific publishers, reported that China had surpassed the U.S. to claim the top spot in the Nature Index for natural sciences. Additionally, a recent report indicated that by 2024, China was home to 369 unicorn startups (compared to about 700 in the U.S.), with nearly a quarter focused on AI and semiconductor sectors. Companies like Huawei have become such formidable tech giants that Chris Miller asks nervously in Chip War: “Could the United States allow a Chinese company like this to succeed?”

China’s rapid advances in science and technology raise a fascinating question that Mokyr’s theory seems unable to fully address: can innovation flourish and economic growth be sustained under an authoritarian regime like modern-day China?

If China were isolated from the global science enterprise, I would respond with a resounding “NO.” History has shown that when intellectuals are not allowed to freely speak their minds—as seems to be the case in China today—the market of ideas withers, dragging down opportunities for creative disruption and sustained economic growth.  However, could China simply grab the fruits produced by the global science enterprise, without ever having to maintain a thriving market of ideas of her own?  Could Chinese intellectuals and entrepreneurs continue to be creative and productive in advancing science and technology, even while their other rights, including freedom of speech, are severely impaired?

These are open questions.  However, the U.S., understandably anxious about her security, is not taking any chances. In recent years, she has taken drastic steps to restrict China’s access to cutting-edge technology and to limit interactions between the scientific communities of the two nations, particularly in areas with potential national security implications.   It is disheartening to see the leader of the free world openly retreating from a foundational principle of that world: that science should be freely accessible to all for progress and prosperity.   America’s China Initiative may also lend credibility to the popular narrative of Chinese nationalists that the so-called Westerns values are mere disguise for self-interests –– or worse, deep-seated racism against non-white people.

It is too early to determine whether America’s isolation measures will be effective, or even necessary, in curbing China’s ambition to lead global innovation in the coming century. What we can say with some certainty is that a less open science enterprise will be less vibrant and productive, and likely a less desirable place for scholars, especially those who are stuck between a rock and a hard place.  Politicians and strategists who support the China Initiative argue that this is a price worth paying to protect our freedoms and uphold the liberal world order. Only time will tell if they are right.

Marco Nie， Wilmette

September 22， 2024