jack-o’-lantern effect
n.— «The plan’s gradual morphing reflects a desire to avoid what planners refer to as the “jack-o’-lantern” effect—sparse redevelopment in a sea of abandoned properties—while still allowing homeowners and residents to directly influence the course of rebuilding through their own actions.» —“Proposal: Let residents decide” by Gordon Russell, Frank Donze Times-Picayune (New Orleans, La.) Dec. 19, 2005. (source: Double-Tongued Dictionary)