David Edward Card (born 1956) is a Canadian-American labour economist and the Class of 1950 Professor of Economics at the University of California, Berkeley, where he has been since 1997. He was awarded half of the 2021 Nobel Memorial Prize in Economic Sciences "for his empirical contributions to labour economics", with Joshua Angrist and Guido Imbens jointly awarded the other half.

David Card was born in Guelph, Ontario, in 1956, to a family of dairy farmers. Card is a graduate of John F. Ross Collegiate Vocational Institute, in which he attended from 1970 to 1975. Card was originally pursuing a degree in physics, before switching to economics during his undergraduate studies. He then earned his Bachelor of Arts degree from Queen's University in 1978 and his Ph.D. degree in economics in 1983 from Princeton University, after completing a doctoral dissertation titled "Indexation in long term labor contracts" under the supervision of Orley Ashenfelter.

Card began his career at the University of Chicago Graduate School of Business, where he was assistant professor of Business Economics from 1982 to 1983. He was on the faculty at Princeton from 1983 to 1997, before moving to the University of California, Berkeley. He then served as a visiting professor at Columbia University 1990 to 1991. From 1988 to 1992, Card was Associate Editor of the Journal of Labor Economics, and from 1993 to 1997, he was co-editor of Econometrica. From 2002 to 2005, he was co-editor of The American Economic Review.

In the early 1990s, Card received much attention for his finding, together with his then Princeton University colleague Alan B. Krueger that, contrary to widely accepted beliefs among economists, the minimum wage increase in New Jersey did not result in job reduction of fast food companies in that state. While the methodology (see difference in differences) and its claim have been disputed (see minimum wage for discussion), later studies of minimum wage increases have tended to confirm Card and Krueger's findings, and many economists, including Joseph Stiglitz and Paul Krugman, accept these findings.

David Card has also made contributions to research on immigration, education, job training and inequality. Much of Card's work centers on a comparison between the United States and Canada in various situations. On immigration, Card's research has shown that the economic impact of new immigrants is minimal. Card has done several case studies on the rapid assimilation of immigrant groups, finding that they have little or no impact on wages. For example, Card studied the economic impacts of the Mariel boatlift, and compared the economic effects in Miami to those in Atlanta, Houston, Los Angeles and Tampa, which receive fewer Cuban immigrants. Card found that despite the drastic increase in low-skilled labor in Miami by 7%, wages for the low-skilled workers were not significantly affected. Furthermore, he found that overall unemployment rates and wages for the labor market as a whole in Miami were unchanged by the sudden influx of immigrants. In an interview with The New York Times, Card said, "I honestly think the economic arguments [against immigration] are second order. They are almost irrelevant."

Despite the fact that Card sometimes researches issues with strong political implications, he does not publicly take a stand on political issues or make policy suggestions. Nevertheless, his work is regularly cited in support of increased immigration and minimum wage legislation.

He served as the expert witness for Harvard in the 2018 Harvard admissions case.

David Card has made influential contributions to the economics of education by studying how access and school environments affect long-term outcomes. In one of his studies, Card used proximity to colleges as an instrumental variable. Results showed that people who lived closer to universities were more likely to enroll. Because of the additional years of schooling, this translated into higher earnings. Card’s work helped prove that there are other factors that affect earnings and play a key role, like schooling. He also found that smaller class sizes, staff income, and resources can affect students' prospects, especially for those from disadvantaged backgrounds. His findings encouraged economists to consider how educational environments can affect inequality over time, and his studies helped broaden how economists think about education by highlighting the importance of real-world variation, institutional differences, and student experiences. His work played an important role in shifting the field toward a more careful empirical design and helped establish education as an area where credible causal evidence could be used to understand economic mobility and opportunity. These contributions were part of a broader empirical movement recognized when Card received the 2021 Nobel Memorial Prize in Economics Sciences.