In this special issue of Behavioural Public Policy, Michael Sanders, Veerle Snijders and Michael Hallsworth, members of the the UK Behavioural Insights Team (BIT), first up offer their reflections on the opportunities and challenges facing the use of behavioural science in policy design and implementation. The special issue then continues with a number of responses to the views presented by Sanders et al. These responses are written by academics from various disciplinary backgrounds (i.e., philosophy, political science, economics and psychology); by people from the private commercial sector (i.e., from a bank, a consultancy and an advertising agency); and by people engaged, or recently engaged, as policy-makers (i.e., the former Head of the UK Civil Service, Lord Gus O'Donnell, and Varun Gauri from the World Bank). The issue finishes with Sanders et al. responding to the responses.

BIT was the world's first dedicated behavioural science unit at the central government level, and therefore Sanders et al. are well placed to reflect on the issues that people working in this relatively new field of public policy face. By convening a multidisciplinary and multisectoral set of perspectives in response, these considerations are, we feel, further enriched. We hope the reader feels the same.