The GATT/WTO Article XXIV prevents a customs union (CU) from raising its common external tariff. In this paper, we compare CU formation with and without this Article XXIV constraint. We show, in a multi-country oligopoly model, that for a given CU structure, Article XXIV improves world welfare...

Why is further multilateral trade liberalisation proving so difficult to achieve? This paper shows that Article XXIV itself, the set of WTO rules governing trade block formation, undermines the multilateral liberalisation process. Trade block formation under Article XXIV can be thought of as a...