Introduction to the SI: Conceptualizing the Effects of COVID-19 on Urban Conditions and Urban Governance in a Polycrisis Environment

The COVID-19 pandemic constituted a profound disruption to urban life worldwide, sharply altering social practices, economic activity and demographic dynamics. While many studies have examined specific short-term consequences of the pandemic, comparatively little attention has been paid to how its effects interacted with other simultaneously unfolding crises and how disruptions might translate into permanent effects, embedded into a larger systemic conceptualization. This Special Issue addresses this gap by situating the pandemic within a broader polycrisis context, in which long-term structural stresses and fast-moving triggers intersect across economic, social, demographic and political systems. Drawing on systems thinking and the emerging polycrisis framework, we conceptualize how pandemic-induced changes in three urban domains—economic restructuring, demographic and migration shifts, and housing market transformations—have produced complex and uneven community-level effects. We further highlight how modes of policy and governance response have shaped outcomes, noting that actions taken to mitigate immediate impacts have often reinforced underlying systemic stresses or generated new risks. The contributions to this Special Issue present empirical evidence from cities across the Global North, illustrating both shared dynamics and diverse local trajectories. Together, these studies provide a foundation for understanding how crises may act as catalysts, accelerators or turning points in urban development. They underscore the need for analytical and policy approaches capable of addressing interconnected risks and supporting socially cohesive, resilient and sustainable urban futures in an era where polycrisis is becoming the new normal.