This paper considers the political economy environment that an antitrust agency is operating in and asks under what circumstances a consumer surplus standard yields higher welfare than a welfare standard. In particular, we address how institutional settings-such as transparency and accountability-interact with the choice of an appropriate standard. We consider a framework in which the antitrust agency can be influenced by third parties (at a cost in terms of real resources) and in which the agency is imperfectly monitored. A welfare comparison between the two standards reveals that neither standard dominates. The consumer surplus standard is attractive relative to a welfare standard, when lobbying is efficient, when accountability is low, where mergers are large and when a marginal increase in merger size is highly profitable.