The study of the relationship between the structure of the industry and market power has been one of the most discussed topics in microeconomic literature. In this research, we focus on the “New Empirical Industrial Organization” (NEIO) approach and particularly on the models developed by Bresnahan (1982) and Lau (1982), and Porter (1983) to analyse the effect of several mergers and acquisitions that took place in the US copper Industry during the period 1994-2009 on market power. We found that although the industry was highly concentrated, the results suggest that mergers and acquisitions had no effect on market power and the industry remained competitive during this period.