Analyzing adverse effects of subway extension on housing prices in affluent urban neighborhoods

This study examines the effects of subway extension on housing prices in affluent urban neighborhoods, focusing on the Q-line extension in Manhattan, New York City. Utilizing synthetic controls and treatment effects estimators, distinct pricing trends across property types are revealed, particularly condominiums. The observed pricing dynamics deviate from the assumption that increasing supplies are associated with price discounts. Moreover, the connection between price discounts and noise complaints is not observed, highlighting the significant role of demand-side factors, especially neighborhood characteristics, in shaping housing prices. An unexpected demographic shift is observed, suggesting that the Q-line extension may disproportionately benefit non-white and low-income groups, challenging the prevailing gentrification narrative. We use the term “inverse premiumization” to denote the phenomenon where anticipated price increases in affluent neighborhoods due to transit improvements fail to materialize. Furthermore, our analysis of speculative behavior reveals a spike in short-term growth during the public notice period, gradually slowing down during construction and operation phases. These findings offer the nuanced adverse effects of subway extension on housing prices, contributing to our understanding of short-to medium-term price premiums and discounts. These insights are key considerations for city planners and policymakers navigating urban development, housing market, and speculative behavior dynamics. •Examines the short-to medium-term impact of the Q-line extension on housing prices in affluent urban neighborhoods.•Reveals that increases in supply not necessarily lead to price discounts.•Uncovers unintended benefits of subway extension for non-whites and low-income groups.•Introduces the concept of “inverse premiumization” related to gentrification and speculative behavior.•Provides a comprehensive analysis of the relationship between subway extension and property values.