Three U.S.-based economists won this year’s Nobel Prize in economics on Monday for revolutionizing empirical research by drawing conclusions from natural experiments, the Royal Swedish Academy of Sciences said.

David Card at the University of California, Berkeley, will receive one half of the 10 million Swedish kronor ($1.1 million) prize for his contributions to labor research by using natural experiments to analyze “the labour market effects of minimum wages, immigration and education.”

The other half of the prize will be shared equally by Joshua Angrist at the Massachusetts Institute of Technology, and Guido Imbens at Stanford University, for demonstrating how precise conclusions about cause and effect can be drawn from natural experiments like those conducted by Card.

Screenshot taken from a live stream on the Nobel Prize official website shows David Card, Joshua Angrist and Guido Imbens as they are announced as the winners of the 2021 Nobel Prize in economics. (Kyodo)

“Their research has substantially improved our ability to answer key causal questions, which has been of great benefit to society,” Peter Fredriksson, the chair of the prize committee, said in a statement.

The award is formally called the Sveriges Riksbank Prize in Economic Sciences in Memory of Alfred Nobel. Unlike the prizes established under Nobel’s will, the economics prize was created by Sweden’s central bank in 1968 and was first awarded the following year.

The economics award concluded this year’s series of Nobel prizes. The awards for medicine, physics, chemistry, literature and peace were announced last week.