Which action is NOT prohibited by antitrust laws for competing brokers?

Receiving compensation from both the buyer and the seller is not prohibited by antitrust laws for competing brokers. This practice, often referred to as dual agency, is generally permissible as long as it is disclosed to all parties involved and they agree to it. Many real estate transactions involve this arrangement where the broker represents both the purchaser and the seller, allowing them to facilitate the deal while earning a commission from both sides.

In contrast, the other actions mentioned, such as boycotting other brokers, dividing the market, or agreeing to set sales commissions, directly undermine competition, which is the very focus of antitrust laws. These laws exist to promote fair competition in the marketplace and discourage practices that can lead to monopolistic behavior or unfair advantages among brokers.