This paper considers the effect of taxes on the definition of relevant markets in antitrust analysis by examining various measures used within the hypothetical monopoly test. We show that the use of net margins (between producer prices and marginal cost) is a proper correction, but that it is...

Professor Louis Kaplow's proposal to abandon market definition in estimating market power has been criticised by a number of scholars. Both the proposal and its criticism were analysed theoretically. The recent Chinese case of Qihoo v. Tencent provides an empirical examination of the proposal...

There are well-known theoretical concerns regarding the use of price correlations to determine antitrust markets. However, this has not deterred their use or the application of Granger causality, stationarity, and cointegration tests in the determination of antitrust markets. In this paper, we...

This paper questions whether markets need contain products that are direct substitutes for consumers. It shows that there are many instances where markets consist of products that are not direct substitutes, and those which consumers cannot directly use or are at different functional levels in...

Monopolization, in the United States, and abuse of dominance, in the European Union, embody different philosophies about how best to police single firm conduct in competition law. Surprisingly, their disagreement ends at market definition. Both doctrines define relevant markets by similar...