Book excerpt: Public policy can be considered a design science. It involves identifying relevant problems, selecting instruments to address the problem, developing institutions for managing the intervention, and creating means of assessing the design. Policy design has become an increasingly challenging task, given the emergence of numerous ‘wicked’ and complex problems. Much of policy design has adopted a technocratic and engineering approach, but there is an emerging literature that builds on a more collaborative and prospective approach to design. This book will discuss these issues in policy design and present alternative approaches to design.