Modeling Processes of Neighborhood Change

TL;DR

This work addresses how fairness-driven transit planning can trigger second-order neighborhood changes and displacement. It introduces a no-regret dynamics framework in a multi-agent setting where residents repeatedly choose housing sites under a cost that combines affordability, amenity access, community ties, and upkeep. The model yields a time-averaged approximate equilibrium and is tested with a case study in Williamsburg, Brooklyn, showing how transit amenities and zoning density can lead to suburbanization of poverty, localized heterogeneity near amenities, or urbanization of poverty followed by segregated cores, depending on density and community-ties preferences. The findings highlight the need for algorithmic planning tools that anticipate spillovers and guide equitable infrastructure design, while outlining limitations and directions for extending the framework.

Abstract

An urban planner might design the spatial layout of transportation amenities so as to improve accessibility for underserved communities -- a fairness objective. However, implementing such a design might trigger processes of neighborhood change that change who benefits from these amenities in the long term. If so, has the planner really achieved their fairness objective? Can algorithmic decision-making anticipate second order effects? In this paper, we take a step in this direction by formulating processes of neighborhood change as instances of no-regret dynamics; a collective learning process in which a set of strategic agents rapidly reach a state of approximate equilibrium. We mathematize concepts of neighborhood change to model the incentive structures impacting individual dwelling-site decision-making. Our model accounts for affordability, access to relevant transit amenities, community ties, and site upkeep. We showcase our model with computational experiments that provide semi-quantitative insights on the spatial economics of neighborhood change, particularly on the influence of residential zoning policy and the placement of transit amenities.

Figures (3)

• Figure 1: Organized opposition to high-density housing development in Berkeley, California. Figure \ref{['fig: coalitional']}: A yard sign with the message "Let's welcome new neighbors, not new towers" and an accompanying website address. Figure \ref{['fig: transit']}: North Berkeley BART station serving the same neighborhood. Source: First author.
• Figure 2: Equilibria for $\lambda = 0.25$ (i.e., residents favor amenity access)
• Figure 3: Equilibria for $\lambda = 0.75$ (i.e., residents favor community ties)