This article uses dynamic panel data analysis to examine the impacts of regulatory reforms in the electricity sector. We find that short term negative effects of ownership unbundling are approximately cancelled out by later positive impacts. Third party access seems to allow taking the benefits but avoiding the costs of ownership unbundling. The implementation of electricity exchanges has a positive impact on end user prices and thus appears to reveal real costs and risk of electricity production. The independency of regulatory authorities shows to have lagged price decreasing influence. Further, market coupling activities in South America, the object under study, seem to merit further expansion.