The Determinants of OPEC Market Share Stability

Abstract

The objectives of this dissertation are to explain the production behavior of OPEC's member countries from 1971 to 1987 and to determine whether there was any structural shift in OPEC's production behavior after the organization attempted to assign a quota to each member. This study focused on political and social as well as economic variables, in order to overcome the misspecification of previous models. In order to achieve the above objectives, the study used the following four models, with modifications: the cartel, competitive, target revenue, and property rights models. The double log multiple linear regression technique was used to operationalize the cartel, competitive, and target revenue models; simple linear regression was used to estimate the property rights model. The cartel model was based not only on economic variables but also on social and political variables. The internal political instability of each OPEC country was measured by the number of armed attacks within the country. The structural shift in OPEC's production behavior between the 1971-1982 period and the 1983-1987 period was evaluated using the Chow-test. The Chow-test showed no significant difference between these two periods for OPEC overall or for individual members. Thus, the two periods were combined so that the study was performed for the entire 1971-1987 period. Because this period of analysis was relatively short, alternative models were applied to pool the data and thereby increase the reliability of the model estimates. A cross-sectional correlated and time-wise auto-regressive model (CCTA) was selected to pool the data and to estimate OPEC's production coefficients. Then each individual OPEC member's production model was estimated and compared to the pooled model. The results indicate that OPEC behaved as a cartel, and that a partial market-sharing hypothesis was significant for all 11 OPEC members. These findings indicate that OPEC was a loose cartel, with only partially effective cooperation on production decisions. Political instability was found to be significant (at the 10-percent level) overall, and it negatively affected production. It was also significant at the 5-percent level for the price-pusher group (Iran, Venezuela, and Algeria). This group was also the only one pooled using least squares with dummy variables (LSDV), because of its common slope and different intercepts. Overall results suggest that OPEC members were basing their production decisions on crude oil prices, excess production capacity, and each member's share of total OPEC output.