A new book by Associate Professor Esmé Shirlow that explores deference in international adjudication has been lauded as a “ground-breaking” study and “tour de force” by legal scholars and jurists.
Published by Cambridge University Press, Judging at the Interface: Deference to State Decision-Making Authority in International Adjudication analyses the approaches to deference taken by the Permanent Court of International Justice, the International Court of Justice, the European Court of Human Rights, and investment treaty tribunals in more than 1,700 decisions between 1924 and 2019.
The international law scholar’s book is preceded by a foreword by Judge James Crawford, and has received praise from experts including Judge Joan Donoghue, now President of the International Court of Justice.
“Dr Shirlow's ground-breaking study of multiple dispute settlement mechanisms combines empirical, inductive and comparative inquiries to shine light on the diverse ways in which deference operates in international courts and tribunals, deepening our appreciation of particular institutions and providing rich comparisons among institutions and over time,” she said.
Professor Jorge E. Vinuales of Cambridge University also hailed the book as a breakthrough.
“Deference is one of those rare concepts that are as pervasive as they are difficult to chart, not only conceptually or phenomenologically, but legally. Dr Shirlow has cracked this intractable equation with impressive analytical distance and great pragmatism. Her study is an important contribution from both a theoretical and a practical perspective,” he said.
In this Q&A, Dr Shirlow traces the origins of her monograph and how it sheds light on the evolving nature of deference in international adjudication.
1. What inspired you to explore the topic of this book?
I first got the idea for this project when I was working in the Attorney-General’s Department on the Philip Morris tobacco plain packaging claim. This was a case filed under a bilateral investment treaty between Australia and Hong Kong by a foreign company, which sought compensation from Australia in relation to Australia’s tobacco plain packaging measures (which the company contended damaged its intellectual property rights). The issue of deference ran across many aspects of that case. For example: the High Court of Australia had ruled that the measure did not “appropriate” Philip Morris’ intellectual property under the constitution, and – had the case proceeded to the merits – the international tribunal would have had to consider whether the High Court’s ruling was relevant in any way to its decision about whether an “expropriation” of property had occurred under the treaty. Australia also asked the tribunal to defer to its policy assessments that tobacco plain packaging would be effective in cutting smoking rates. It submitted that it was for Australia – and not an international tribunal – to make public policy assessments of that type. Ultimately that case was dismissed at the jurisdictional stage so we don’t know how the tribunal would have resolved these questions. But this is just one of many international disputes which raise these questions around whether an international court or tribunal should defer to domestic decisions and, if so, how to achieve such deference. These are the types of cases and questions I investigate in this book.
2. What were some of the challenges in your research and were you surprised by any of the trends or findings you uncovered?
The main challenge I initially faced was one of methodology. I wanted to investigate how international courts and tribunals approach issues of deference in practice, and so I needed to find a way of doing that which was both methodologically defensible and feasible. Having worked as a lawyer on these types of claims, I knew that international courts and tribunals have considerable discretion to determine how to approach deferring to domestic decisions as these issues are rarely addressed in treaties or procedural rules. As such, the method I selected was to review a set of decisions from four international courts and tribunals to identify (and compare) their approaches to deference. In the book I explain the methodology I developed to do this, which integrated social sciences qualitative and inductive methods of coding with legal theories about adjudication and authoritative decision-making. This was important to leverage the strengths of empirical and doctrinal techniques, while minimising their weaknesses. It also ensured that the empirical study of adjudicative reasoning could remain ‘internal’ to the discipline of law despite borrowing methodological techniques and theories from ‘external’ disciplines. The methodology means that the book analyses the legal dimensions of deference, without losing sight of how adjudication functions as a political and authoritative practice.
The second challenge that arose was associated with analysing the data coming out of my coding of international adjudicative decisions. Applying the same methodology to analyse all of the decisions allowed me to identify deference in individual cases and also draw out trends in approaches to deference over time and in the cases of different international courts and tribunals. In the book, I connect the empirical data to a conceptual theory about deference by grouping all of the approaches to deference that I identified into seven ‘modes’ of deference. These modes reflect relationships between international adjudicators and domestic decision-makers of submission, deferral, abstention, restraint, reference, respect and control/dismissal. I show that underlying these seven modes of deference are distinct structures of authority. International adjudicators select between the seven modes of deference depending upon whether they view decision-making authority as conclusive, suspensive or concurrent. Adjudicators adopting a conclusive view of decision-making authority favour categorical approaches to deference: one actor’s decision controls the outcome of another actor’s decision‑making process. Suspensive authority, by contrast, precludes the exercise of one actor’s authority in favour of another, either for a limited period of time or in respect of particular topics. Concurrent authority arises where two decision‑makers work in tandem, their decision-making processes being viewed as complementary rather than incompatible or exclusive. This supports the identification of the systemic function of deference, with deference emerging through the analysis as a key tool used by international courts and tribunals to regulate the interface between the domestic and international legal orders.
One key surprise was how often international courts and tribunals consider whether to defer to domestic decisions in international adjudication, with some form of deference being applied by some courts in almost 50 per cent of their decisions. Looking at the data systemically revealed another surprising finding: that different international courts and tribunals at different times have exhibited diverse deference profiles, all reflecting distinct ways of analysing and structuring the domestic/international interface.
3. Your book examines the shifting nature and structure of adjudication under international law and its relationship to domestic decision making authority. What factors have led deference to become such a hotly contested field in international adjudication? What forces are driving these changes?
Deference mediates conflicting claims to decision-making authority from domestic government officials on the one hand and international courts and tribunals on the other. It provides a means for international courts and tribunals to determine if – and how – domestic decisions on certain topics will be given some relevance to their own decisions on those topics. As such, ostensibly technical debates about deference reflect more fundamental debates about the appropriate balance of decision-making authority between international and domestic actors.
This explains why many scholars argue in favour of, or against, specific approaches to deference. However, as international law evolves, so too do perceptions of the proper relationship between domestic decision-makers and international adjudicators. Deference provides a lever by which this relationship can be set and modified over time. Approaches to deference depend heavily upon how international courts and tribunals conceive of their role, legitimacy and expertise relative to that of domestic actors. This indicates that deference is likely to differ depending on a range of factors, including historical context, geographical factors, the background and skills of adjudicators, and the claim structure and caseload of international courts. Deference can only achieve its function if it remains malleable enough to balance and adjust these factors as they arise in individual cases. So, the book illustrates the value of examining deference conceptually and systemically for what it reveals about international adjudication and the international/domestic interface, rather than focussing on attempting to ‘fix’ or direct approaches to deference once and for all.
4. Does this book build on any of your previous research?
The book builds on, and benefits from, my experience of advising States and investors in international proceedings. The issues addressed in the book arise increasingly in international adjudication, reflecting that international law has expanded in recent years to cover a diverse array of subjects, prompting qualitatively different and quantitatively increased opportunities for overlap and interaction between domestic and international decision-making. I have also examined these interactions in much of my academic work, including a number of works focussing on deference specifically (including two pieces in the ICSID Review – Foreign Investment Law Journal, and a chapter in an edited collection with Oxford University Press). I was also invited to contribute the entry on ‘deference’ to the Max Planck Encyclopaedia of International Procedural Law, which builds on the conceptual approach to analysing deference that I set out in the book but also extends this to relations between international courts/tribunals themselves.