In particular, by the creation of free-trade and preferential trading areas; economic and monetary unions; and common markets.

A preferential trading area, under which each member state agreed to make concessions to the others not available to other nations, has been bogged down in red tape since it was established in 1993.

The 1983 agreement by eighteen countries to set up a regional preferential trading area (PTA) in East and Southern Africa has been little more successful in overcoming three familiar problems.

Depending on the level of economic integration, trade blocs can fall into different categories, such as: preferential trading areas, free trade areas, customs unions, common markets and economic and monetary unions.