Despite significant theoretical advances in social and behavioural macroeconomics, little has been done to synthesise the disparate developments in these fields and point the way forward to future research directions and policy implications.  This book reviews, unifies and extends diverse strands of thinking and shows how these theories can be used to improve macroeconomic modelling for policy development in a range of spheres. The book explores how the most empirically relevant socio-behavioural traits can widen the scope of macroeconomics to fruitfully address new issues and challenges, such as rising inequality, the change in the functional distribution of income (labour and capital shares), and a further understanding of the government spending multiplier. Chapters also address more traditional topics such as macroeconomic policy effectiveness, growth, saving and labour supply. Other, more open-ended themes of the book include whether the concept of individual rationality should be complemented by collective rationality; whether socio-behavioural traits underlie socially inefficient outcomes such as tragedies-of-the-commons, rat races, financial crises and global warming; and whether such traits can provide new foundations for (New) Keynesian macroeconomics. This book will be essential reading for advanced researchers and students working in macroeconomics and other social sciences, including psychology and politics, as well as those working on the theoretical end of public policy.