The growth rates of Intra-GCC trade is not anticipated, in the short run, to reach the rates achieved by the European Union. A study made by the Secretariat prior to the formation of the customs union estimated that the growth of Intra-GCC trade would be 6-30% during the first four years. Those estimations were based on factual basis and were calculated using peer experiences based on the "GCC Integrational Model" due to the great similarity among the economies of the GCC States, the structural characteristics of these States and the continuous trade-restricting conditions during the transitional period.

In order to identify the actual advantage of the GCC customs union in such a short time, it was necessary to measure the growth rate of Intra-GCC trade after the formation of the GCC Customs Union and compare that growth rate with the historical growth average of the Intra-GCC trade before the formation of Customs Union.

To this effect, detail studies have been conducted. Such studies have analyzed the volume of Intra-GCC trade during the period 1993-2004 in order to be able to compare the volume of Intra-GCC trade before and after the creation of the GCC Customs Union.

It was surprising that those studies have indicated a high growth rate in the Intra-GCC trade after the formation of the Customs Union on the 1st of January 2003. That growth was beyond all expectations because the volume of Intra-GCC trade has increased from US$ 11.6 billion in 1993 to US$ 20.3 billion in 2002, i.e. an increase by 75.5% over the past ten years or an average annual growth accounting for some 7.5%.

After the formation of the customs union in January 2003, the volume of Intra-GCC trade has increased by an annual growth average that exceeded 20%.