Sendhil Mullainathan is a Professor of Economics at Harvard, and a recipient of a MacArthur Foundation 'genius grant'. He conducts research on development economics, behavioural economics, and corporate finance. He is Executive Director of Ideas 42, Institute of Quantitative Social Science, Harvard University. Eldar Shafir is William Stewart Tod Professor of Psychology and Public Affairs at Princeton University. Most of his work focuses on descriptive analyses of inference, judgement, and decision making, and on issues related to behavioural economics.