Behavioural economics aims to test and refine the assumptions made in the 'standard' model of economic behaviour, which presumes that consumers are perfectly rational. It draws on insights from psychology to understand various phenomena that economists have historically tended to neglect, such as self-control problems, biases in the way consumers process information and the importance of the way different options are presented to consumers. Research in this area can help us to build better models of consumer behaviour and to achieve a better understanding of the impact of policy changes on people's wellbeing.