Definitions: Gentrification By The Book

window sign, Fort Point, South Boston, MA

gen·tri·fi·ca·tion  \ˌjen-trə-fə-ˈkā-shən\ noun 1964: the process of renewal and rebuilding accompanying the influx of middle-class or affluent people into deteriorating areas that often displaces poorer residents
(Merriam Webster)

Gentrification and urban gentrification denote the socio-cultural changes in an area resulting from wealthier people buying housing property in a less prosperous community. Consequent to gentrification, the average income increases and average family size decreases in the community, which may result in the informal economic eviction of the lower-income residents, because of increased rents, house prices, and property taxes. This type of population change reduces industrial land use when it is redeveloped for commerce and housing. In addition, new businesses, catering to a more affluent base of consumers, tend to move into formerly blighted areas, further increasing the appeal to more affluent migrants and decreasing the accessibility to less wealthy natives.
(Wikipedia)

Window bars and chain-link give way to modern boxes with maximum square footage in Venice, CA

"In the classic gentrification pattern, architects, artists, gays, and young professionals discover a run-down
neighborhood, buy real estate when it's still a bargain, and spark a run on contractors, who take on months-long
renovation and restoration projects. Commercial gentrification usually is quick to follow - an initial rush of coffee bars
and exciting bistros, followed by a kind of sheepish regret as the dry cleaners and hardware stores disappear."
(Anthony Flint, Boston Globe May 29, 2005)