What type of antitrust violation occurs when brokerages agree to stop running advertisements in a local publication?

The scenario described involves brokerages colluding to stop running advertisements in a local publication, which constitutes an agreement among them to limit competition in that specific market. This is classified as group boycotting, a form of antitrust violation where businesses collectively refuse to deal with a particular company or market participant.

By agreeing not to advertise, the brokerages are effectively trying to pressure the publication and eliminate a marketing avenue that could benefit competitors. Such actions can distort market competition by restricting choices for consumers and reducing the overall availability of information about the services provided by the brokerages. The intent is often to harm a competitor’s ability to operate successfully, which undermines the principle of fair competition that antitrust laws are designed to protect.

In contrast to group boycotting, the other violations like price fixing involve agreements to set prices at a certain level, market allocation refers to dividing markets among competitors, and bid rigging pertains to manipulating the bidding process. None of these accurately represent the actions described in the question, which specifically focuses on limiting advertising through collective refusal.