Blockbusting

n. practice of persuading homeowners to sell property at low prices by appealing to racist fears that minorities will move into the neighborhood and depress property values

Blockbusting is a practice used mostly by real estate agents and developers to encourage property owners to sell by giving the impression that a neighborhood is changing.
See more at Wikipedia.org...

Attempt to manipulate sale prices of real property by making representations as to crime rate or ethnic ratios. - (read more on Blockbusting)