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 and its claim has been disputed by some, many economists, including Joseph Stiglitz and Paul Krugman, accept Card and Krueger's findings. David Card has also made fundamental 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. In an interview with The New York Times, Card said, "I honestly think the economic arguments are second order. They are almost irrelevant." This does not imply, however, that Card believes immigration should be increased, merely that immigrants do not pose a threat to the labour market. 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 was the recipient of the 1995 John Bates Clark Medal, awarded to "that American economist under the age of forty who is judged to have made the most significant contribution to economic thought and knowledge." He gave the 2009 Richard T. Ely Lecture of the American Economic Association in San Francisco. A 2011 survey of economics professors named Card their fifth favorite living economist under the age of 60. Along with N. Gregory Mankiw, he was elected vice president of the American Economic Association for 2014. He has received along with Richard Blundell the 2014 BBVA Foundation Frontiers of Knowledge Award in Economics, Finance and Management category for "their contributions to empirical microeconomics," in the words of the jury’s citation. "Motivated by important empirical questions, they developed and estimated appropriate econometric models, making significant methodological contributions in the process. Both are known for their attention to institutional detail, careful and innovative research design, rigorous application of econometric tools, and dispassionate reporting of results."
