Final answer:
The real estate broker is engaging in blockbusting, an illegal practice that exploits racial fears to manipulate property sales and promote segregation. Blockbusting was outlawed by the Fair Housing Act of 1968, but discrimination in housing can still occur clandestinely.
Step-by-step explanation:
A real estate broker advising owners to sell their properties by suggesting that it would be advantageous to do so because members of minority groups are moving into the neighborhood is engaging in a discriminatory and illegal practice known as blockbusting. Blockbusting is a tactic that plays on the fears of property owners, convincing them to sell at reduced prices due to the false belief that incoming minority residents will devalue their homes. This unethical strategy promotes segregation and preys on racial discrimination.
Such practices were condemned and became illegal following the Fair Housing Act of 1968, which outlawed blockbusting as part of a broader move to prevent discrimination in housing. Blockbusting, along with other discriminatory practices like steering and mortgage discrimination, has contributed to residential segregation over the years. Despite legal prohibitions, there is evidence to suggest that various forms of housing discrimination still persist today, though often in more clandestine ways.