(a) A customs union is the form of economic integration where all barriers are
removed on trade between member countries. In addition, a common tariff is imposed on trade with the rest of the world.
(b) A customs union can speed up economic growth through the following means:
(i) large scale production;
(ii) efficiency in production;
(iii) being an effective bargaining force;
(iv) pooling resources together;
(v) attraction of foreign investment.