Howlett M., Pung How Y. & del Rio P. (2015) The parameters of policy portfolios: verticality and horizontality in design spaces and their consequences for policy mix formulation. Environment and Planning C: Government and Policy 33(5): 1233-1245

Abstract. Policies increasingly come in complex packages and understanding the nature of design criteria for such portfolios is increasingly important. However, existing studies of policy mixes fail to carefully define the dependent variable of the inquiry. As a result, theorization of policy design has lagged, the cumulative impact of empirical studies has not been great and understanding of the phenomena, despite many observations of its significance in policy studies, has not improved significantly over the past three decades.