This Handbook is a unique and original contribution of over thirty chapters on behavioural economics. It examines and addresses an important stream of research where the starting assumption is that decision-makers are, for the most part, relatively smart or rational. This particular approach is in contrast to a theme running though much contemporary work in which individuals' behaviour is deemed irrational, biased and error-prone, often due to how the brain is hardwired. In the smart people or bounded rationality approach, where errors or biases occur and when social dilemmas arise, more often than not, improving the decision-making environment can repair these problems without hijacking or manipulating the preferences of individuals. The Handbook covers a wide-range of themes from micro to macro, including economic psychology, heuristics, fast and slow thinking, neuroeconomics, experiments, the capabilities approach, institutional economics, methodology, nudging, ethics and public policy. It argues that neoclassical decision-making benchmarks are typically not the gold standard for best practice. The expert contributions demonstrate that decision-making capabilities and decision-making environments can both be more effective and consistent than nudging in improving welfare and utility, and in maximizing well-being. They also demonstrate how learning, improved information, empowerment, voice and preference play a vital role in determining smart decision-making outcomes. This comprehensive and original Handbook will appeal to academics in behavioural and experimental economics, and economic psychology.Contributors include: M. Altman, C.L. Anderson, G. Antonides, M. Augier, S. Austen, N. Berg, P. Biscaye, P.J. Boettke, S. Bourgeois-Gironde, R.A. Candela, A. Cronholm, G. Danese, G. Foster, R. Frantz, P. Frijters, K. Gangl, H. Gintis, M.J.J. Handgraaf, B. Harrison, B. Hartl, A. Hopfensitz, S. James, B. Kamleitner, E.L. Khalil, R. Kheirandish, D. Kilger, E. Kirchler, F. Kutzner, D. Lester, A. Leung, E. McPhail, B. Meder, T. Mengay, L. Mittone, S. Mousavi, H. Neth, A. Ortmann, M. Pingle, O. Powell, O. Rosin, T.F. Rötheli, N. Sari, N. Shestakova, L. Spiliopoulos, V. Tarko, S. Teraji, J.F. Tomer, J. van Beek, T. Vogel, B. Yang Lester