The report provides an in-depth assessment of the electricity wholesale markets in Belgium, Germany, Spain, France, the Netherlands and Great Britain with a view to determining how competitive markets were in 2003, 2004 and 2005. The report provides summary key results for traditional market structural indicators, electricity-specific measures of market structure and market outcome measures. It also provides the results of a range of statistical analysis. The main results are also subjected to sensitivity tests and a range of alternative scenarios are assessed.