[Prof. Dr. Anne van Aaken is Professor of Law and Economics, Legal Theory, Public International Law and European Law at the University of Sankt Gallen, Switzerland.]
I am delighted that
Tomer Broude commented on Opinio Juris on the potential and the pitfalls of the use of behavioral economics in international law and am equally happy that I am able to follow up on this. I will do so in two steps: the first part will address the benchmark against which Behavioral International Law and Economics (BIntLE) should be measured in my view. The second mentions some of the applications I suggest in
my paper and in an
earlier article. Tomer and I are currently planning a book together, bringing together the insights of both of our papers and extending them considerably.
In
his introduction to the topic, Tomer comments on the relationship of “Behavioral International Law” to rational choice approaches in international law and international relations.
Behavioral Economics is an empirically validated theory about human behavior. There are of course competing theories in social science. The psychological research is not free-floating and it is not used as such in the field of international law and international relations. Tomer suggests as a basis from which to depart sociological approaches. Sociology as such does not have a unified behavioral model, thus one would need to clarify which sociological theories are drawn upon (e.g. the homo sociologicus as advanced by Ralf Dahrendorf (micro theory of individual behavior), system theory (macro theory), etc.). I suggest as a benchmark rational choice theory, for two reasons. First, the psychological insights we use are commonly named behavioral
economics, given that this research tests and challenges the rational choice hypothesis to a hitherto unknown extent (and the psychologist Daniel Kahneman won the Nobel prize in economics). But behavioral economics is not yet at a stage where it has a unified behavioral theory replacing rational choice: many heuristics and biases depend on the decision-making context (those have to be studied carefully). Rational choice is still the benchmark against which the insights are measured. Second, the parsimony of rational choice makes it a natural starting point. Since behavioral research adds complexity (something which every academic should try to avoid if a simpler explanation is possible for answering a certain research question), it has to show that it generates better insights and is able to explain phenomena which cannot be explained drawing on the rational choice approach alone. To use a coin minted by Einstein: “Everything should be as simple as it can be, but not simpler.” A rational choice approach might sometimes be too simple. Tomer and I share the belief that behavioral economics is able to generate more and better insights to the functioning of international law and we share also the deliberations on the methodological problems this might generate. Because of the weight I put on parsimony, I shift the burden of proof on BintLE to show that it might generate better insights than a rational choice approach to international law. This has to be done step by step, analyzing different fields of general and special international law. After all, it will be the empirics which will validate (or not) the research hypotheses advanced by any theory: the proof of the pudding is in the eating.
Having said that, let me turn to some promising insights, adding to Tomer´s suggestions in his paper and his post.
