As graduate students at Princeton University in the late 1980s and early 1990s, we were fortunate to study with David Card, who on Monday was awarded the 2021 Nobel Memorial Prize in Economic Sciences.
David, along with Joshua Angrist and Guido Imbens, whose contributions were also awarded a Nobel this year, changed the way economics is practiced. He changed our lives and those of many former students. Here, we highlight his extraordinary accomplishments as a scholar, but also as a teacher and mentor. David is now at the University of California, Berkeley.
The three award recipients were leaders in the “credibility” revolution in economics, and social science more broadly. Correlation is not the same as causation. Any student of introductory statistics knows that.
Sometimes, though, we can do something to separate the two. The Nobel winners developed techniques that bring the idea of scientific experiments to social science: They exploit “naturally occurring” events, or “experiments,” in the real world that help create situations where an intervention affects some people, but not others, for reasons unrelated to the outcomes being studied.
Their work is marked by the incredible care with which they wield these powerful tools and examine their limits.
The economists brought these tools and insights to a staggering array of subjects. David’s work addressed traditional concerns of labor economics — how wages are determined, the role of unions, determinants of unemployment and the like.
His focus also extended outward to other traditional topics in social insurance, such as examining the role that Social Security and Medicare, unemployment insurance and others play in the economy and in individual lives. It also extended further to issues of broader social importance, including immigration and education (K-12 and higher education).
What David’s contributions also teach us, though, are that the tools he helped develop can be applied to a range of issues not traditionally within the focus of economic analysis.
It was once standard — and misguided — to think that there was real, hard-hitting economics, and then there was “soft” stuff about topics that affect families, children and women. Also on Monday, the day the Nobel prize was announced, the National Bureau of Economic Research released David’s co-authored new working paper on workplace gender diversity.
David’s work and that of his students demonstrate that universal preschool, or caregiving, or the role of teacher quality, are areas where economics can make meaningful contributions. The fact that these tools of credible econometric reasoning are so broadly applicable helped inspire multitudes of students to pursue economics.
Pride of teaching
And then there is the direct teaching itself. The suite of offices at Princeton at the time was centered around a tall counter; so important was this design feature that he brought it with him to his Berkeley offices. His students know that when he comes out for a coffee break, he is always eager to chat about their work. Those casual chats about their (our) research proved invaluable to scores of his students. His classroom instruction was impeccable, but nothing could match 15 minutes at the counter.
And, anyone who has had an early draft edited by David knows that conveying information is incredibly important: putting together tables or graphs so that the content is easily conveyed is an art form. Spending time on the writing itself is critical. Back in the day, well before the advent of Dropbox, David’s comments on a hardcopy draft would come back with handwritten comments everywhere, including on slips of paper inserted into the draft with an X-Acto knife and Scotch tape!
David’s record is studded with rich collaborations with a remarkable array of economists. He has spent a significant amount of time and effort in the last few years organizing conferences and editing volumes that honor the contributions of others, including those who were taken from us far too soon — Alan Krueger, Bob LaLonde, and John DiNardo.
His is a legacy of generosity and collaboration that has yielded some of the most important insights in economics in a generation. If they gave Nobel prizes for teaching, and mentoring, and collaborating, Dave should get those too.
Phillip B. Levine is an economics professor at Wellesley College. Kristin F. Butcher is the director of the Center on Children and Families at the Brookings Institution and an economics professor at Wellesley College.