An important presumption underlying the smart mixes approach is that ‘complementarity’ adds to the ‘smartness’ of an instrumental mix; however, the questions of what complementarity actually means, in what forms it may occur, and when it can be said to be smart must be answered. This chapter focuses on these questions, considering complementarity between public and private actors in the regulatory and enforcement space from both theoretical and practical perspectives by looking into the goals, nature and dynamics of public-private interaction in several areas. It also assesses when and how public-private complementarity may contribute to an effective smart mix and what contextual factors may affect this. However, public-private regulatory and enforcement regimes will only be truly smart and effective when they are perceived as legitimate – and consequently followed up on – by those affected by them. This chapter argues the importance of taking greater account of the role of the law in this regard, not only to fully explain public-private complementarity, but to fully assess whether this represents a smart mix or not and how the law may impact on the shaping of a smart mix both now and in future, inducing certain limits so as to secure its legitimacy.

The idea of improving the performance of environmental policies by combining various instruments and approaches in a smart way is attractive. However, from a theoretical perspective, the idea of optimal mixes seems problematic. This chapter starts from the assumption that governance fields (i.e. the multiple institutions, both public and private, that are operating within a given policy arena across multiple levels) can be best described as complex systems, and consequently develops an argument about the usefulness of complexity sciences in studying smart policy mixes. The area of climate change governance after the Paris Agreement serves as our empirical illustration.

There is a growing body of literature that explores the effectiveness of different regulatory approaches and tools. This is sometimes referred to as smart regulation, responsive regulation, risk-based regulation or instrument choice theory. Much of this literature is focused on articulating and evaluating the design of regulatory principles and it is focused at local or national regulation. According to this literature, it is generally accepted that a mix of complementary regulatory techniques is desirable and that these should be adapted to specific contexts. It is often asserted that regulation should be effective and efficient. There is infrequent consideration of how smart regulation could be applied to regulatory issues at the level of international law. Elements of this appear in literature on corporate social responsibility. Smart regulation is implicit in areas where ‘regulatory toolkits’ are advocated such as in the Food and Agriculture Organization of the United Nations (FAO) Code of Conduct for Responsible Fisheries. Typically, this involves combinations of rights-based measures (private property rights and market-based controls) with traditional ‘command and control’ type rules, and the use of both soft and hard law instruments. More generally, the development of cross-cutting regulatory agendas, such as the use of trade measures to secure environmental goals, is synonymous with smart regulatory approaches. If such approaches are to succeed, then we need to consider the effectiveness of different instrument combinations. Drawing on key regulatory design principles, this chapter considers the extent to which international fisheries law satisfies key design principles (including coherence, complementarity, efficiency, and scalability). It finds that whilst many are satisfied, this is hampered by the range of actors engaged in international regulatory activities, the limited tools available to regulators and the absence of strong reflective and adaptive governance structures. The latter in particular present challenges for effectiveness because they limit possibilities for change and improvement. Of course, this may simply be a matter of perspective, and if we look ‘inside’ international fisheries regulation, and it view regulation as cutting across international and domestic fora, then possibilities for more sophisticated and reflective regulation exist. Here a smart regulatory agenda is likely to strengthen the interface between domestic and international dimensions of fisheries regulation.

This chapter describes and explores the effectiveness of regulatory mixes in different governance arrangements in (offshore) oil production. The changing role of states has resulted in the coexistence of state-based, market based and hybrid governance arrangements at different levels that have the authority to evoke compliance from those who are ruled. This chapter discusses the regulatory mixes in three oil production governance arrangements, which differ in forms of authority and levels of governance: first, the development of market-based arrangements of Dutch offshore oil platforms; second, the development of Social Licence to Operate arrangements in the Arctic; and third, the development of benefit-sharing arrangements between oil companies and indigenous communities. This chapter not only gives insight in the coexistence of governance arrangements governing the offshore oil production in different institutional settings, but also the different regulatory mixes within these arrangements. For each of these governance arrangements the regulatory mixes (policy instruments) are described and their effectiveness is evaluated. In other words, are the regulatory mixes in these governance arrangements smart? Do they contribute to changes in the behaviour of public and private actors (outcome), and do they contribute to the solution of environmental problems (impact)?

This chapter analyses the adoption and deployment of traditional ‘command-and-control’ regulations and ‘new’ environmental policy instruments (NEPIs) as they occur in practice in five different jurisdictions, namely Austria, Germany, the Netherlands and the United Kingdom (UK) as well as the European Union (EU) since the early 1970s. It focuses on three different types of NEPIs – informational instruments, voluntary agreements and market-based instruments – and examines how and why they have become mixed in different jurisdictions. It argues that while there has been a significant uptake of NEPIs in all five jurisdictions, important differences have remained regarding the composition of instrument mixes in particular jurisdictions. Adopting a longitudinal perspective allows for the identification of leaders, followers and laggards for different types of NEPIs. Although there may be a theoretical ‘optimal mix’ of policy instruments, in reality patterns of adoption and deployment are very strongly influenced by a mixture of contingent factors, which vary within and across jurisdictions, over time.