A conceptual model of transit-spurred gentrification in London

Monday, July 20, 2026, 11:00 AM

Session: SOC Poster Session (Overflow) (In-person)

London is scoping major transit investments amid an acute housing shortage. Recent policy proposals treat transit as a precondition for new housing, but the policy environment around the line extension (i.e. planning permissiveness, affordability requirements, and build speed) determines whether the original community is preserved or displaced. This paper presents a minimal system dynamics model (five stocks, six flows) of transit-spurred gentrification in a single, hypothetical London neighborhood. The model tests three policy levers: transit extension delivery time, NPPF density reform, and affordable home share. Under status-quo parameters (10-year build, no NPPF reform, current Section 106 norms), the model produces 218 of 2,500 original residents (~9%) displaced over 20 years. Three scenario findings: 1) NPPF reform alone prevents displacement entirely; 2) strong affordability alone reduces displacement it by approximately one third; 3) cutting build time from 10 to 5 years alone increases displacement to 270. The model suggests delivery acceleration and planning permissiveness are conditionally complementary -- beneficial for the original community only when layered. Submitted as a work-in-progress for feedback on conceptualization and structure.