The hidden bias of the Vienna Convention on the International Law of Treaties

The process of treaty formation and reservations to multilateral treaties, enshrined in Articles 19-21 of the Vienna Convention on the Law of Treaties, establishes the principle that reservations are reciprocal. The treaty will be in force between a reserving state and a non-reserving state as amended by the reservation. Therefore a state that wants to exempt itself from a treaty obligation must let other nations escape that same burden. This paper presents an economic model of treaty formation and considers the effect of reciprocity on treaty ratifications among heterogeneous states. The model reveals that the Vienna Convention creates a strategic advantage for states with high costs and low benefits.