(a)Customs Union is an agreement among nations to eliminate trade barriers such as tariffs, quotas etc, among themselves or members and to adopt common barriers to imports from non-member countries.
(b) Advantages of Customs Union are:
(i) Enhanced welfare for the citizens.
(ii) Improved efficiency and stimulation of faster economic development.
(iii) Lower costs per unit due to internal economies reaped by producing for a large market.
(iv) A larger internal market for members and increased trading activities between member countries.
Disadvantages of Customs Union are:
(i) Possible death of some industries resulting in some degree of frictional unemployment.
(ii) Loss of revenue that would have accrued as a result of abolition of tariffs.