Africa is awash with regional economic communities (RECs). Indeed, as far back as 1976, Ajomo picturesquely described the ‘mercurial proliferation and disappearance’ of regional economic institutions in Africa. For political, economic and strategic reasons, many countries belong to more than one REC. The multiplicity of RECs and the concomitant multiple state memberships have created a complex patchwork that complicates decision-making for states, community officials, individuals and businesses. In what is, to date, the only detailed, continent-wide empirical study into the effect of the twin phenomena of many RECs and multiple memberships, the United Nations Economic Commission for Africa (UNECA) concluded that the phenomena impact negatively on the achievement of the goals of the African Economic Community (AEC). In June 2009, some member states – Kenya and Uganda – could not join the newly formed COMESA customs union as they belonged to the EAC customs union. The phenomena also impact negatively on Africa's international trade relations. In the recent EU-led Economic Partnership Agreements negotiations, countries in Eastern and Southern Africa – the regions where the phenomena are most prevalent – had to form new regional groupings for the purposes of the negotiations.