Irrationality: What, Why and How

This thesis has made a special effort to explore some relevant issues on (ir)rationality. Chapter 2 and Chapter 3 answer the question what is irrationality. Chapter 2 improves the methodology to measure irrationality by proposing a new incentive system on individual decision-making: the prior incentive system (Prince). Chapter 3 addresses the issue of irrationality in decisions under ambiguity. Chapter 4 answers the question of why we steer people away from irrationality. Chapter 4 discusses whether we should correct people's irrationality by imposing a better decision when freedom of choice cannot be realized. Chapter 4 concludes with recommending strong paternalism and provides a litmus test for people's views on paternalism. Chapter 5 answers the question how to make people less irrational. Chapter 5 studies the social influences on people's decision-making processes and offers possible approaches to nudge people away from irrationality.