IN THE FACE OF GENTRIFICATION:

Case Studies of Local Efforts to Mitigate Displacement.
Diane K. Levy, Jennifer Comey, Sandra Padilla (2006). [White paper]. Washington, DC:
Metropolitan Housing and Communities Policy Center, the Urban Institute.

This paper defined getrification as “the process whereby higher-income households move into low-income neighborhoods, escalating the area’s property values to the point that displacement occurs." (p. 1). It points out revitalization as the first stage of one of the earliest sign of gentrification, writing:

Neighborhoods showing signs of revitalization with the possibility of future gentrification—evidence of housing improvements and increased housing prices in an area proximate to other gentrifying neighborhoods—are characterized as the early stage. (p. 2)

The gentrification of Uptown

A highlighted program is "Chicago Partnership for Affordable Neighborhoods (CPAN), which was implemented citywide in 2001. CPAN is a voluntary program where developers and aldermen from each ward determine the number of affordable units, if any, developers will set aside in their market-rate developments. ...
While CPAN is a citywide program, it is at the discretion of each alderman whether developers must participate.
...
Another problem inherent in a voluntary program is whether developers will choose to participate or take their business elsewhere. Aldermen have leverage only if the developer needs zoning approval. (p. 71)

With this respect, the authors noted that "some developers believe that only elected official’s support is necessary to approve housing development" (p. 72), emphasizing that residents can organize around issues. (But how? Did the gentrification occur because of lack of residents resistance or grassroots organization?)