Introduction

This introductory chapter provides a background to the nature, purposes, and mode of operation of the customs union as one special form of tariff unification. The customs union is a type of arrangement that eliminates or reduces the tariff barriers between two or more political units while maintaining tariff barriers against imports from outside regions. The historical importance of customs union derives largely from the fact that in the 19th century the widespread existence of contractual obligations not to resort to tariff discrimination tended to restrict the field for special tariff arrangements between independent countries.