Three US-based academics on Monday won the Nobel Economics Prize for research on the labour market using "natural experiments", or observational studies, that have revolutionised empirical research in the field, the jury said. Canadian-American David Card, Israeli-American Joshua Angrist and Dutch-American Guido Imbens shared the prize for providing "new insights about the labour market" and showing "what conclusions about cause and effect can be drawn from natural experiments," the Nobel committee said in a statement. The Economics Prize wrapped up a male-dominated 2021 Nobel season which saw a total of 12 men win prizes and only one woman. Card won half of the 10-million-kronor (€1 million) prize for work focused on the labour market effects of minimum wages, immigration and education. The Canadian-born professor at the University of California in Berkeley was caught off guard by the nod. "I don't think I would have been a very high probability," he told the Nobel Foundation, explaining that he was talking to them wearing pyjamas. In natural experiments, researchers study the result of chance events or policy changes on groups of people, unlike other experiments where...