This article seeks to assess the impact of liberalisation and privatisation on performance in the generation segment of the electricity supply industry. Regulatory indicators for a panel of 19 OECD countries over a 10 year time period were constructed to examine the influence of regulatory reform on efficiency and price, and to assess the relative efficacy of different reform strategies. The presence of data with both cross-country and time-series dimensions allows separate identification of country specific and regulatory effects. The primary findings are that while changes in legal rules may be slow to translate into changes in conduct, unbundling of generation, private ownership, expanded access to transmission networks, and the introduction of electricity markets impact various aspects of performance in a statistically significant way.