摘要:The objective of this study is to investigate potential market power exertion in the output market of the ethanol-producing sector using the Solow Residual-Based (SRB) test and its different modalities (primal and primal-dual). The markup estimates (Lerner’s index) obtained using ethanol imports and processed crudel oil as instrumental variables to estimate the primal SRB are compared to the primal-dual SRB estimates. For both approaches, a statistically significant positive markup was estimated implying the presense of market power exertion. Both markup estimates are relatively close to each other.