The thesis examines competition and efficiency in the liberalised electricity industry of England and Wales after 1990. Literature review and economic analysis is undertaken for four activities: generation and trading arrangements; transmission pricing; comparative efficiency in distribution; and competition and access in supply. In trading arrangements and distribution, the analysis is supplemented by empirical work using both event study models and non-parametric efficiency analysis. Broad conclusions are that there is some evidence of generators behaving strategically in the pool, and productivity is variable among the distribution companies, with the increase attributable to the industry as a whole.