Policy formulation relies upon the interplay of knowledge-based analysis of issues with power-based considerations, such as the political assessment of the costs and benefits of proposed actions, and its effects on the partisan and electoral concerns of governments. Policy scholars have long been interested in how governments successfully create, deploy and utilise policy instruments, but the literature on policy formulation has, until now, remained fragmented. This comprehensive Handbook unites original scholarship on policy tools and design, with contributions examining policy actors and the roles they play in the formulation process.