2021 Nobel Memorial Prize in Economic Sciences

The 2021 Nobel Memorial Prize in Economic Sciences was divided one half awarded to the American-Canadian David Card (born 1956) "for his empirical contributions to labour economics", the other half jointly to Israeli-American Joshua Angrist (born 1960) and Dutch-American Guido W. Imbens (born 1962) "for their methodological contributions to the analysis of causal relationships." The Nobel Committee stated their reason behind the decision, saying:

"This year's Laureates – David Card, Joshua Angrist and Guido Imbens – have shown that natural experiments can be used to answer central questions for society, such as how minimum wages and immigration affect the labour market. They have also clarified exactly which conclusions about cause and effect can be drawn using this research approach. Together, they have revolutionised empirical research in the economic sciences."

Card's key contributions on economics were the natural experiments on labour economics (including difference in differences). Angrist and Imbens' contributions were on the local average treatment effect and natural experiments to estimate causal links.