Market definition and market power in competition analysis: some practical issues

Abstract: Market definition plays a key role in competition analysis and has often proved controversial. However, it is merely a means to an end, the real issue being to establish whether or not firms have significant market power, i.e. the power to increase prices. This objective is rather different to the traditional neo-classical economic view of a market. The introduction of the SSNIP test in the US Department of Justice 1982 Merger Guidelines resulted in the development of new methods for defining markets and for measuring market power directly, thus eliminating the need to define the market at all.