The journey to a Nobel Prize often begins in unexpected places. For Guido Imbens, it started in the unglamorous setting of a Harvard University laundromat. During his early years teaching at Harvard, Imbens, now a distinguished figure in econometrics, would spend Saturday mornings with his colleague Joshua Angrist amidst the hum of washing machines. These were not mundane chores, but rather fertile ground for intellectual exchange. As clothes spun, so did ideas, with Imbens and Angrist delving into complex questions about economics and the world around them. These seemingly casual weekend conversations, nearly three decades prior, resurfaced vividly in Imbens’ memory when he learned that he and Angrist were joint recipients of the prestigious 2021 Nobel Prize in Economic Sciences, recognizing work born from those very laundromat dialogues.
“We were discussing research ideas, contemplating unresolved questions, and it’s truly remarkable to think that our work evolved directly from those moments… essentially, it was there that we conceptualized the core ideas that underpin this Nobel Prize,” Imbens reflected.
Guido Imbens holds esteemed positions as the Applied Econometrics Professor at Stanford Graduate School of Business, Professor of Economics in the School of Humanities and Sciences, and Senior Fellow at the Stanford Institute for Economic Policy Research (SIEPR).
The Royal Swedish Academy of Sciences bestowed half of the 10 million Swedish kronor (approximately $1 million USD) prize – formally known as the “Sveriges Riksbank Prize in Economic Sciences in Memory of Alfred Nobel” – upon Imbens and Angrist. This honor recognized their “methodological contributions to the analysis of causal relationships.” The other half of the prize was awarded to David Card from the University of California, Berkeley, for his “empirical contributions to labour economics.”
Stanford President Marc Tessier-Lavigne lauded Imbens’ achievement, stating, “On behalf of the Stanford community, I extend my heartfelt congratulations to Guido Imbens on this extraordinary accomplishment. Professor Imbens has been pivotal in reshaping how researchers approach and understand causal relationships. His insightful framework, co-developed with his esteemed colleague and fellow laureate Joshua Angrist, has empowered researchers across economics and related fields to harness natural experiments for addressing critical societal and global questions. Stanford takes immense pride in his accomplishments.”
Throughout his distinguished career, Guido Imbens has been instrumental in tackling the inherent limitations of real-world social science experiments. His groundbreaking work has significantly enhanced the ability of researchers to rigorously evaluate the effects of various interventions using both field and experimental data. The methodologies pioneered by Guido Imbens are now indispensable for analyzing intricate research questions, ranging from assessing the efficacy of novel pharmaceuticals to determining the broader economic impact of new regulatory policies.
“Receiving the telephone call was utterly astonishing,” Imbens shared during a question and answer session hosted by the Royal Swedish Academy of Sciences immediately following the announcement. “I was absolutely overjoyed upon hearing the news, and particularly thrilled to be sharing this recognition with Josh Angrist and David Card, both of whom are close friends and esteemed colleagues.”
This Nobel Prize for Guido Imbens marks another milestone for Stanford’s economics department. Just a year prior, Stanford economists Paul Milgrom and Robert Wilson were awarded the same prestigious prize. Furthermore, Alvin Roth, another Stanford economist, was a Nobel laureate in 2012, cementing Stanford’s position as a leading institution in economic research and thought leadership.
The Genesis of Groundbreaking Econometric Methods
Those formative Saturday mornings at the Harvard laundromat were more than just chore time for Guido Imbens and Joshua Angrist. They were intellectual sparring sessions, fueled by discussions of cutting-edge research and the latest economic papers.
Both were then junior assistant professors at Harvard (Angrist is currently an economist at MIT), and as Guido Imbens recounted during a virtual press conference hosted by Stanford, their intellectual connection was immediate.
This partnership led to the development of a pioneering econometric model known as the Local Average Treatment Effect (LATE). Introduced in their seminal 1994 Econometrica paper, “Identification and Estimation of Local Average Treatment Effects,” the LATE model provided researchers with a robust framework for drawing causal inferences from observational data.
Guido Imbens and Angrist focused on harnessing the power of natural experiments. These leverage real-world situations where chance or naturally occurring randomization takes place, contrasting with controlled laboratory conditions that are often expensive, time-consuming, and ethically problematic in social science contexts. Their work demonstrated how these natural experiments could be rigorously employed to evaluate cause-and-effect relationships in complex scenarios.
The LATE model has profoundly reshaped research practices across econometrics and various statistical disciplines. Many of Guido Imbens’ publications from the 1990s are now recognized as among the most frequently cited in economics research, underscoring the lasting impact of his methodological contributions. Guido Imbens further elaborated on his work in his comprehensive 2015 book, co-authored with Donald B. Rubin, titled Causal Inference for Statistics, Social, and Biomedical Sciences (Cambridge University Press). This book serves as a definitive guide for researchers seeking to apply these methods.
By effectively utilizing natural experiments, the LATE model enabled Guido Imbens and other researchers to rigorously investigate causal phenomena and address critical issues facing both the public and policymakers. For instance, to examine the effects of unearned income on labor supply, Guido Imbens ingeniously used data from a real lottery to analyze whether unearned income altered people’s incentives to work.
In collaboration with Donald Rubin of Harvard and Bruce Sacerdote of Dartmouth, Guido Imbens conducted a survey of Massachusetts lottery participants. The Massachusetts lottery system, uniquely, distributed winnings incrementally over many years rather than as a single lump sum, mimicking the structure of a guaranteed basic income. By comparing the behavior of lottery winners to non-winners, the researchers could effectively isolate and infer the causal effects of guaranteed income on labor supply.
Their findings revealed that while unearned income did have some impact on labor supply, it did not significantly alter the amount of work undertaken by individuals. “Even without conducting a controlled experiment, we were able to derive substantial insights into the causal effects of labor supply in this specific context,” Guido Imbens explained.
This type of sophisticated statistical modeling, pioneered by Guido Imbens, provides invaluable tools for policymakers evaluating the potential effects of federal or state assistance programs, as he noted in an interview with Stanford News Service.
“We can use lottery winnings as an instrument to estimate the effect of unearned income on labor supply, a crucial factor in the design of social security systems,” Guido Imbens stated. “This research demonstrably showed how to obtain credible and robust results using these methods in real-world, complex settings.”
Another landmark study, co-authored by Joshua Angrist and the late Alan Krueger, applied the LATE model to examine the causal relationship between education levels and income. Their research compellingly demonstrated that students compelled by compulsory education laws to remain in school for an additional year subsequently experienced higher earnings throughout their careers.
During the Monday virtual press conference, Guido Imbens poignantly acknowledged the loss of a key collaborator.
“Alan Krueger, uniquely, co-authored papers with David Card, Josh Angrist, and myself. His untimely passing a few years ago is a profound loss. We deeply miss him and wish he could be here to share this momentous occasion with us,” Guido Imbens shared with heartfelt sentiment.
Shaping Policy and Econometric Methodology
Guido Imbens’ groundbreaking work has provided crucial insights for governments and policy institutions in the design and evaluation of economic policy interventions, particularly in areas like education and labor markets.
“It has been incredibly rewarding to witness the widespread adoption and interest in these methods within the economics profession,” Guido Imbens remarked.
However, the path to recognition for Guido Imbens and Angrist’s innovative approach to addressing societal issues was not immediate. When they initially embarked on this research in the early 1990s, their unconventional methodologies attracted limited attention. Looking back, Guido Imbens now believes this initial obscurity may have been a hidden advantage. “In retrospect, that period was incredibly beneficial, providing us with the space and freedom to delve deeply into these complex issues without external pressures or scrutiny,” Guido Imbens reflected.
He acknowledged that there were times when the work felt “somewhat isolating,” but the presence of Angrist as a close colleague, alongside other supportive figures in his former department at Harvard, including Rubin and the late Gary Chamberlain, fostered an exceptionally supportive and intellectually stimulating environment.
Guido Imbens maintains strong friendships with both of his fellow Nobel laureates. Angrist had the honor of serving as the best man at Guido Imbens’ wedding to Susan Athey, who is herself a distinguished economist – the Economics of Technology Professor at Stanford GSB and a senior fellow at SIEPR. During Guido Imbens’ tenure teaching at UC Berkeley in the early 2000s, he and Card frequently worked late into the night. After concluding their work, they would often share drinks, providing Guido Imbens with invaluable learning opportunities about research methodologies and the types of impactful questions Card pursued.
“Sharing this Nobel Prize with both of them is an immensely gratifying experience,” Guido Imbens concluded.
Mentoring the Next Generation of Econometricians
Since the publication of his seminal paper with Angrist nearly three decades ago, Guido Imbens has witnessed a significant surge in student interest in econometrics and causal inference.
Guido Imbens, pictured center-left with his wife, Susan Athey, and their three children. The image captures Guido Imbens with his family shortly after receiving the call informing him of his Nobel Prize in Economic Sciences.
Michael Pollmann, a current PhD student in economics under Guido Imbens’ supervision, recalls a particularly impactful comment from his mentor: “Professor Imbens remarked that when we encounter aspects of our research that remain unclear, that’s precisely where the greatest interest and potential lie. These areas of uncertainty highlight opportunities for new learning and for contributing to a broader understanding of these questions.”
Pollmann emphasizes that Guido Imbens, both as a researcher and as a mentor, empowers his students to effectively leverage available data to address critical research questions.
“He champions a two-step approach: first, identifying what we still need to understand, and subsequently, devising rigorous methods to achieve that understanding,” Pollmann explains.
While Guido Imbens’ scholarship is deeply rooted in theoretical research and methodological rigor, he consistently emphasizes the importance of grounding research in empirical observation and real-world understanding – a principle he diligently instills in his students.
“I strive to convey to my students that the most effective path to impactful methodological research involves actively engaging with those conducting empirical work and policy-relevant analyses. This ensures that the methodological advancements we develop are directly applicable, relevant, and readily utilized by researchers analyzing real-world data,” Guido Imbens explains.
“He Won”: A Family Celebration
For Guido Imbens, a particularly cherished aspect of receiving the Nobel Prize was the opportunity to celebrate this monumental achievement with his family. The preceding days had already been filled with excitement in the Imbens-Athey household. Just the week before, Susan Athey, Imbens’ wife, who broke ground as the first woman to receive the prestigious John Bates Clark Medal in 2007, was elected president-elect of the American Economic Association.
The Nobel Prize announcement, delivered in the early hours of Monday morning due to the time difference between California and Stockholm, Sweden, where the Nobel committees convene, awakened the entire Imbens household.
Carleton Imbens, Guido Imbens’ 17-year-old son, vividly described the scene at their home upon receiving the trans-Atlantic phone call informing them of his father’s Nobel Prize: “I woke up around 2:30 AM to complete pandemonium. Everyone was running around. My mom burst into my room and quickly shared the incredible news. Initially, I wasn’t entirely sure what the day ahead would entail, and I briefly thought I should just try to get back to sleep before school. However, it quickly became clear that sleep was no longer on the agenda.”
Athey, with a touch of parental understanding, told their three children, “You can decide if you want to go to school today or not.”
The Imbens children have absorbed a considerable amount of knowledge about their parents’ work through family dinner conversations. “While they are usually more interested in other scientific fields, they occasionally humor their parents by engaging with econometrics,” Athey chuckled.
Thus, Imbens’ daughter, Sylvia, immediately grasped the significance of the moment when her mother opened her bedroom door and simply announced, “He won.” “We had been jokingly placing bets on the Nobel Prize. We didn’t actually believe my dad was going to win,” admitted 10-year-old Sylvia Imbens.
Despite the abrupt awakening, the children enthusiastically rallied to celebrate, Athey recounted. “My oldest son sprang into action, searching for an extension cord, and my youngest eagerly answered the door when the doorbell rang, wanting to get everyone coffee.”
Sylvia Imbens, while still grasping the intricate details of her father’s research, clearly recognized his unwavering dedication. “I know how much effort he invests in his work, so it feels incredibly rewarding to see him receive this recognition,” she said with pride.
Athey warmly noted how touching it was to witness the children’s pride in their father, whom they affectionately call “Pap.” “He is an exceptional father, dedicating so much time to our children. It was truly heartwarming to see their overwhelming excitement for him,” Athey shared.
Originally hailing from the Netherlands, Guido Imbens’ academic journey began at Erasmus University Rotterdam and the University of Hull in England. He earned his master’s and PhD degrees in economics from Brown University in 1991. His academic career includes positions as an assistant and later associate professor at Harvard University from 1990 to 1997, and again from 2006 to 2012. He joined Stanford University in 2012. He also held professorships at the University of California at Los Angeles (1997-2001) and the University of California at Berkeley (2002-2006). Guido Imbens holds an honorary doctorate from the University of St. Gallen.
His scholarly achievements are further recognized through fellowships in prestigious organizations including the Econometric Society, the American Academy of Arts and Sciences, the Royal Holland Society of Sciences and Humanities, the Royal Netherlands Academy of Sciences, and the American Statistical Association.
Media Contacts
E.J. Miranda, University Communications: [email protected]
