Joel Mokyr’s intellectual journey to the 2025 Nobel Prize in Economics began at Yale, where he was Ph.D. student in the early 1970s under the mentorship of the late William Parker, a path-breaking economic historian.
Parker, who supervised Mokyr’s thesis, pioneered the systematic use of quantitative data and statistical methods to better understand how economies change over time. His support left a lasting impression on the future Nobel laureate.
“Bill Parker was not just a great economic historian, he was also witty, urbane, and well-read,” Mokyr ’74 Ph.D., the Robert H. Strotz Professor of Arts and Sciences and professor of economics and history at Northwestern University told Yale News this week. “A true intellectual and a thoroughly decent man, a wonderful companion, and a mensch. Yale was a decisive influence on me, best years of my life. Brilliance all around!”
Mokyr, who studies the economic history of Europe, this week was recognized by The Royal Swedish Academy of Sciences for his theory explaining how sustained economic growth occurs. He was awarded half of this year’s Nobel Prize; the other half was awarded to two economists, Philippe Aghion of the Collège de France and the London School of Economics and Peter Howitt of Brown University.
He was focused right from the start and knew what he wanted to do. And he did it.
Richard Levin, the former Yale president and the Frederick William Beinecke Professor of Economics Emeritus, was Mokyr’s classmate in the Ph.D. program.
“Joel was unusual for graduate students in those years in that most of us dabbled around for a couple of years before deciding on a field of specialization, but he arrived already quite determined to be an economic historian,” Levin said. “He was focused right from the start and knew what he wanted to do. And he did it.”
Indeed, Mokyr’s research interests have remained remarkably consistent since his years on the Yale campus, Levin said. He recalled serving as a teaching assistant with Mokyr for economic history class Parker taught that examined how Western Europe experienced sustained economic growth.
“Why did the Industrial Revolution happen there as opposed to elsewhere? What was the secret?” Levin said. “That was a big question that Bill Parker had explored in his research and teaching and that Joel took up with a passion for the rest of his career.”
To continue growing, Mokyr argues, societies must foster a ‘culture of change’ characterized by openness to new ideas and experimentation and a tolerance to change that disrupts existing structures.
Mokyr began his career with case studies of specific countries. His dissertation focused on industrialization and economic development in the Netherlands and Belgium from 1800 to 1850, exploring why these states in northwestern Europe, known historically as the Low Countries, experienced a period of growth before stagnating again. In another book, “Why Ireland Starved,” he analyzed why the Irish economy failed to grow during the first half of the 19th century.
From there, and through a number of books, Mokyr developed his broad thesis that sustained economic growth requires useful knowledge, mechanical competence, and institutions conducive to technological progress. To continue growing, he argues, societies must foster a “culture of change” characterized by openness to new ideas and experimentation and a tolerance to change that disrupts existing structures.
Mokyr is the fourth Yale-trained Nobel laureate in economics in the past four years, joining James A. Robinson ’93 Ph.D., who won the prize last year, and Douglas W. Diamond ’80 Ph.D. and Philip H. Dybvig ’79 Ph.D., who shared it in 2022. The latter two met while they were Ph.D. students at Yale.
Two Yale faculty members — William Nordhaus, Sterling Professor of Economics and Robert Shiller, Sterling Professor Emeritus of Economics — have also won Nobel prizes in economics in recent years. Nordhaus was honored in 2018, and Shiller in 2013.
“Joel very much deserves the Nobel Prize,” Levin said. “He’s clearly one of the preeminent economic historians, if not the preeminent economic historian, of our generation. You could see that potential in him from the beginning. He was intelligent, serious, and motivated. But also, he is a warm spirit, very friendly and generous. I’m thrilled to see him win the prize.”
Mokyr’s influence as a scholarly mentor reaches Yale’s campus. A former student from Northwestern, José-Antonio Espín-Sánchez, is now an associate professor of economics in Yale’s Faculty of Arts and Sciences.
“If you ask me, even as his scholarly contributions are Nobel worthy, I still think Joel’s main contribution to the world is the dozens of students, like me, that he has inspired and mentored to do research, to understand the world we live in, and to do good to others,” said Espín-Sánchez, an economic historian who completed his dissertation in 2014 under Mokyr’s supervision.
Espín-Sánchez says he barely spoke English when he arrived at Northwestern with the goal of working on theoretical corporate finance. Six years later, he completed his thesis and joined Yale’s faculty. He credits Mokyr’s mentorship for that success.
“It is not an exaggeration to say that I could not have done it without Joel,” he said. “And it is not an exaggeration to say that my case is not unusual.”
As a mentor, Mokyr was always accessible and encouraging, Espín-Sánchez said.
“Joel always had nice things to say about the work, even if it was unintelligible, and found a way to motivate me to work harder and think critically of my own ideas,” he said. “But above all, no matter how busy he was, he always found time to meet with me and discuss any of my latest crazy ideas.”
