One of the most discussed contemporary ideas in policy making is Richard Thaler and Cass Sunstein’s proposal to influence people’s choices without coercing them by improving the “architecture” of their choices. Many governments have implemented behaviourally informed policies, focusing on “nudges” – interventions that preserve freedom of choice, but that also steer people in certain directions. This Forum, featuring contributions by Cass R. Sunstein, Lucia A. Reisch, Xavier Troussard, René van Bavel, Monique Goyens, and Daniel M. Hausman, addresses both the opportunities and challenges presented by the application of behavioural insights to policy making. What do citizens actually think about behaviourally informed policies? Is this method of influencing choices ethically acceptable? Should the findings of behavioural economics be alarming to normative economists, in that they threaten the grounds upon which economists evaluate alternatives?