Which of the following practices is considered an antitrust violation in real estate?

Boycotting competitors is regarded as an antitrust violation in real estate because it involves collusion among agents or brokers to limit competition or harm those not part of the agreement. Antitrust laws are designed to promote fair competition for the benefit of consumers and prevent practices that would create unfair advantages or market manipulation. When real estate professionals agree to not work with certain competitors or to undermine their business through collective actions, it stifles competition, restricts consumer choices, and can artificially inflate prices.

In contrast, open houses, advertising properties, and negotiating commissions are standard practices in the real estate industry that do not inherently violate antitrust laws. Open houses serve as a marketing tool to attract potential buyers, advertising is essential for informing the public about available properties, and negotiating commissions is a normal aspect of business dealings between brokers and clients. These activities, when conducted individually, do not manipulate market conditions or restrict competition in the same manner that boycotting does.