文档介绍：23 February 2004

The Customary International Law Supergame:
Order and Law

e Norman*
Joel P. Trachtman**

Abstract

Customary international law is an enigma. It is produced by the decentralized
actions of states, and it generally lacks centralized enforcement mechanisms. Political
science realists and some rationalist legal scholars argue that customary international law
cannot affect state behavior: that it is “epiphenomenal.”

This article develops a model of an n-player prisoner’s dilemma in the customary
international law context that shows that it is plausible that states ply with
customary international law under certain circumstances. These circumstances relate to:
(i) the relative value of cooperation versus defection, (ii) the number of states effectively
involved, (iii) the extent to which increasing the number of states involved increases the
value of cooperation or the detriments of defection, including whether the particular issue
has characteristics of mons problem, a public good, or work, (iv) the
information available to the states involved pliance and defection, (v) the
relative patience of states in valuing the benefits of long-term pared to
short-term defection, (vi) the expected duration of interaction, (vii) the frequency of
interaction, and (viii) whether there are also bilateral relationships or other multilateral
relationships between the involved states.

One implication of this model is to lend credence to customary international law.
From a research standpoint, this model identifies a number of parameters for which data
may be developed in order to test the model. From a policy standpoint, this model shows
what types of contexts, including malleable institutional features, may affect the ability of
states to reach stable and efficient equilibria in their customary international law
relations.

* William and Joyce Cummings Professor of Entrepreneurship