Custom, Public Law and the Human Rights Analogy

Anthea Roberts is a Senior Lecturer in Law at the London School of Economics and a Professor of Law at Columbia Law School.

I always enjoy reading Martins Paparinskis’ work and have read enough of it to know that I can count on him to have (1) written about questions that are of interest to me, (2) engaged in careful analysis, and (3) researched the hell out of the issue. Paparinskis’ breadth across investment treaty law, general issues of international law like state responsibility, and case law in specific fields like human rights law, is truly impressive. I don’t plan to push Paparinskis on his central thesis.  Instead I want to ask three broader questions about how international law is developed and interpreted.

First, Paparinskis begins and ends his book by endorsing Jennings’ quote that the meaning of rules cannot be deduced a priori but instead “must be hammered out in the practice of Governments and by the familiar process of the development of law through its application by international tribunals” (pp 6 and 259). I agree with this point. In practice, however, we see extensive reference to judicial and arbitral decisions, including some that say they are interpreting treaty provisions as free standing norms and others that say they are interpreting the treaty in light of custom. But we see almost no discussion of the actual practice of governments, including in the latter type of case law. Why is that?

One reason is that the test for establishing custom is problematic. Customary international law is ostensibly made through state practice and opinio juris. But practice can be hard to find and cumbersome or difficult to collect. Paparinskis himself notes that the form of practice that we are most likely to see in the investment treaty context is pleadings by states, but this source has a number of shortcomings, including that pleadings are likely to be made by some states frequently and others rarely or not at all, and pleadings tend not to be made publicly available (pp 144-146, 171). (NAFTA is a notable and welcome exception to the latter point.)

Even when we can find smatterings of practice, it is almost impossible to collect real evidence of (1) general and consistent state practice followed out of (2) a sense of legal obligation. Even when people say that they are finding custom, they are usually relying on short cuts, such as referring to case law that says something is custom, General Assembly resolutions that declare something to be custom, or academic articles that opine that something is custom. Almost no one actually “finds” custom. Instead, arbitrators, academics and counsel typically refer to other sources that supposedly have already “found” custom.

The rules for determining custom are not a good description of what any of us actually do. Instead, they are largely used to critique the work of others. For instance, “you say that X is custom” but “you have only referred to the practice of a handful of states” or “you have not proved that those states acted out of a sense of legal obligation.” The bar is so high that everyone fails. Is it possible to reformulate the rules for establishing custom in a way that is theoretically defensible and yet could actually be satisfied as a matter of practice? Could the bar be set at a level that encouraged us to stretch and yet was not clearly out of reach? What sort of evidence could we look for and how much of it would we need? Could the test for custom ever be realistic instead of idealistic?

Second, in the search for relevant practice, I think Paparinskis is too quick to dismiss public law approaches that try to derive the meaning of some treaty provisions by reference to domestic law protections offered in certain capital exporting states (p 173-174). True, this is not what we would think of as custom or general principles in a classic sense because this approach does not refer to the practice of all, or even most, states. But, as Paparinskis himself acknowledges, it would be strange to look for standards of protection from the domestic law of all states given that investment treaties were intended to raise the bar for at least some of those states. Moreover, if we understand part of the objective of investment treaty law as creating protections for investors abroad that are comparable to what they might find at home, there is some justification for looking more narrowly at the protections offered by major capital exporting states.

The way in which this practice is used is also  relevant to how broadly the survey must extend. One of the critiques of investment treaty law is that some tribunals have given content to treaty provisions, like fair and equitable treatment, that exceeds the protections that investors could expect to get under the domestic law of many or even most states. If that is so, then showing that a particular protection is not afforded in the domestic legal systems of major capital exporting states helps to show that such a protection was probably not intended to be given under investment treaties. The legal protections offered by these domestic legal systems might provide a ceiling rather than a floor, i.e., whatever standards investors have been guaranteed as a matter of treaty law, they should not expect to receive more favorable protections abroad than they would receive at home or in major developed states.

As international law increasingly deals with issues that are not purely inter-state but concern relations between individuals and states, we should expect more public law principles to be imported into the system. This happens most readily in areas like human rights, where issues of public law are formulated in international or regional treaties (e.g., the ECHR) and interpreted by international or regional courts (e.g., the ECtHR). But other domestic legal systems offer comparable protections of property rights, due process, and non-discrimination without formulating this as a treaty or permitting interpretation by an international tribunal (e.g., the provisions on takings and due process in the US Constitution). If these domestic public law cases speak to the same types of issues, why not make greater reference to this material in interpreting investment treaties and determining what counts as state practice?

Third, Paparinskis makes a strong case for interpreting investment treaty provisions by reference to human rights law and jurisprudence. He argues that these rules and interpretations of them can be looked at under Article 31(3)(c) as other relevant rules of international law and by way of analogy given that the human rights and investment treaty systems share a number of structural and substantive similarities (p 175-180). I agree with this point. My interest here lies in the politics of the human rights analogy.

In my recent article Clash of Paradigms (AJIL 2013), I identify different approaches to understanding the investment treaty system by reference to paradigms based on public international law, international commercial arbitration, public law, trade law and human rights law. One point I make is that different paradigms are often invoked by some actors rather than others because they tend to highlight the role and interests of that actor. I found this claim relatively easy to make with respect to some of the paradigms, e.g., the public international law paradigm, which usually (though not always) seems to favor states by focusing attention on their role as treaty parties, and the international commercial arbitration paradigm, which usually (though not always) seems to favor investors by focusing attention on them as equal disputants alongside the respondent state.

But I am much less sure that the human rights paradigm tends to consistently favor one set of interests over another. On one level, investors like to invoke the human rights analogy because it casts their rights as being like human rights, i.e., the rights belong to the investors and not their home states and thus investors might receive certain protections against the actions of their home states (e.g., the argument that inter-state countermeasures should not be permitted as a defense to investor-state claims). On another level, the human rights analogy often suggests a more cautious approach to interpreting substantive provisions (e.g., property rights) or to the role of international tribunals (e.g., the margin of appreciation doctrine), which may play to the interests of states rather than investors.

My sense seems in keeping with Paparinskis’ observation that sometimes the very same player invokes the human rights analogy in one context but seeks to reject it in another context (he gives Paulsson as an example, p 179). The divided loyalties of this paradigm would also help to explain why this analogy has gained less traction in practice (to date, at least) than one might expect, given the substantive and structural similarities between the fields, because it does not have an obvious or consistent champion. This issue made me want to ask Paparinskis what he thinks the politics of the human rights paradigm are, particularly as he invokes it here to take a more cautious approach to the content of fair and equitable treatment / minimum standard of treatment.