Unpacking policy portfolios: primary and secondary aspects of tool use in policy mixes

A recent resurgence of interest in policy design has fostered renewed efforts to better understand how specific combinations of policy tools arise and shape policy outcomes. However, to date, these efforts have been stymied by under-theorization of the dif- ferent purposes to which tools are directed in policy mixes and a corresponding failure to acknowledge both these in conceptual work on the subject and in policy practice. Existing frameworks do not adequately recognize the complexity of contemporary policy tool mixes, especially their hybrid and multilayered features, and how procedural and substantial tools operate and interact together in priority and supportive roles. To close this gap, we propose a revised tool framework that distinguishes between first and second-order aspects of instruments used in policy mixes and highlights the particular salience of procedural tools within them.