the effect of oil export concentration on economic growth in opec countries

the organization of the petroleum exporting countries (opec) has a key role in making universal political and economic decisions regarding petroleum. therefore, it seems highly important to assess the opec member’s degree of concentration and its monopoly.  this research, aims to assess and classify the concentration of petroleum export in the opec countries during the 1997-2011 period by the herfindahl- hirschman index method. subsequently the impact of oil export concentration on economic growth of the opec member countries is assessed via the panel data pattern and the fixed effect method.  the research model has been estimated in two conditions. results of the estimation show that in the second condition there is a meaningful and positive relationship between oil export concentration and economic growth rate.