Once proven likely the entity must prove that an entrant would be able to enter the market in a timely fashion in order to pose a genine threat to the incumbent firm (European Union, 2004). If there is too great a time lag the merged entity may benefit from anti-competitive behaviour (such as setting prices above a competitive level) for long enough to create a lasting negative effect before the competitor enters the market. As long as the returns on engaging in such activity are high enough to cover any switching costs and opportunity costs forgone, the trade-off faced by the incumbent favors anti-competitive behaviour, if even only in the short-run, and the threat of potential entry will not have the required restraining affect. This point is reiterrated by McAfee et al. in their paper entitled ‘When are Sunk Costs Barriers to Entry?’, saying, ‘Entrants might
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