This textbook is an introductory guide to applying behavioral sciences and systemic thinking into public policy design and implementation. It presents an innovative public management toolkit to handle 'wicked' social problems - those not very responsive to traditional public policy instruments - by incorporating insights from the behavioral sciences and systemic design in the diagnostics of public problems, based on the motivations and constraints of the 'real citizen' - beyond the ideal citizen's perfectly rational intentions and plans devoid of social context or self-control problems. ...