مازاد مصرف در مقابل استاندارد رفاه در یک مدل اقتصاد سیاسی کنترل ادغام

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.

The purpose of this paper is to evaluate alternative standards that can be assigned to an antitrust agency in charge of merger control. It is striking that some of the major antitrust agencies appear to operate with objectives that differ from welfare maximization. In particular, both the U.S. as well as EU merger control can be interpreted as maximizing consumer surplus rather than aggregate welfare.1 In a world with no regulatory failures, excluding firms' profits from the objectives assigned to the antitrust authority is hard to justify.2 However, in a setting where institutional and political economy considerations are taken into account, the welfare implications of various standards that are given to the antitrust authority are more subtle. In particular, it may be welfare enhancing to assign a standard that is not first-best. This paper considers the political economy environment in which an antitrust agency operates and asks under what circumstances a consumer surplus standard yields higher welfare than a welfare standard.3 In particular, we address how institutional settings—such as transparency and accountability—interact with the choice of an appropriate standard. We model the political environment that the antitrust agency is subject to through a common agency framework (à la Bernheim and Whinston, 1986).4 In this context, interested parties provide inducements to the antitrust agency which are contingent on the outcome of the merger review. More specifically, we consider a situation that can be characterized by a three stage process. In the first stage, a merger is notified and the interested parties provide contingent bids to the agency. In order for the merger to be potentially welfare enhancing we assume that there are efficiency gains, which are known to the firms and the antitrust agency.5 We consider three interested parties: consumers, the merging firms, and the (non-merging) competitors. Consumers do not lobby the antitrust agency. This may arise for at least two reasons. First, consumers may not be well informed about the consequences of proposed mergers (we will assume that consumers cannot observe the characteristics of the merger) and accordingly may not be able to formulate appropriate contingent bids. Second, consumers may face prohibitive transaction costs in representing their interests. These costs could be associated with the traditional problems of free-riding and collective action with numerous agents.

This paper illustrates that the design of a standard that an antitrust agency is held accountable to needs to consider the political economy in which the antitrust agency operates. In particular, we address how institutional settings—such as transparency and accountability—interact with the design questions of choosing an appropriate standard. We find that neither a welfare standard nor a consumer surplus standard dominates. The consumer surplus and welfare standards give rise to different types of inefficiencies: relatively inefficient mergers—which decrease welfare—are pushed through under a welfare standard, while relatively efficient mergers (which would increase welfare) are prohibited under the consumer surplus standard. While lobbying activity is undesirable under a welfare standard, it raises welfare under a consumer surplus standard. The process of lobbying—as characterized by transparency of the lobbying process and accountability of the antitrust agency—is shown to be important in terms of the relative performance of the two standards. Both transparency and accountability make lobbying less effective. Under a welfare standard this has two effects. On the one hand, it will reduce the scope of undesirable deals that firms can manage to push through. On the other hand, transparency and accountability impose a constraint that firms can only circumvent at a cost. By contrast, transparency or accountability do not affect the scope of deals for which a consumer surplus standard is inefficient. It only affects the balance between wrong decisions and waste in lobbying. Higher transparency and stronger accountability actually shift the balance towards wrong decisions because it reduces firms' effectiveness in lobbying. Since wrong decisions are socially more costly than lobbying, transparency and accountability are actually not desirable under a consumer surplus standard.