From Rent Gap to Network Rent Gap: Metro Network Spillovers and Gentrification in Shanghai

ABSTRACT Although metro investment is intended to improve accessibility and promote spatial equity, it may also induce gentrification through physical upgrading and social replacement. Classical rent gap theory explains transit‐induced gentrification primarily through the proximity effects of newly built stations as individual nodes. However, infrastructure nodes are embedded in networks, especially in metro systems, where spillover effects frequently extend beyond directly invested locations. This study, therefore, asks whether rent gaps can also trigger gentrification through network spillovers. To address this question, we extend traditional rent gap theory to a network context by introducing the concept of the network rent gap and applying it to Shanghai's metro system. Using a dual perspective on nodes and the network, we employ a propensity score matching difference‐in‐differences (PSM‐DID) model to examine the gentrification effects of metro expansion from 2011 to 2020. The results confirm that node‐based metro investment contributes to local gentrification. More importantly, we identify a network rent gap mechanism: node‐based metro investment generates stronger gentrification effects in both local and non‐local areas where network centrality increases, including places served only by pre‐existing metro stations. Moreover, gentrification in central urban areas depends more on metro proximity and transfer functions, whereas suburban gentrification is more strongly associated with gains in network centrality. These findings suggest that transport policy should integrate both node‐based and network‐wide perspectives to address spatial equity more effectively.