The Great Migration, Urban Spatial Structure, and Their Economic and Environmental Impacts in the U.S.

Abstract

This thesis investigates the transformative impact of the Great Migration on urban spatial structure in the United States and its subsequent economic and environmental consequences. The Great Migration (1910-1970), marked by significant African American migration from the South to Northern and Western cities, reshaped the demographic and spatial landscape of receiving cities. Yet, the long-term spatial dynamics and their implications remain underexplored, a gap this study aims to address. Using a novel dataset constructed through the City Clustering Algorithm (CCA), this research redefines historical urban boundaries, creating “synthetic cities” (Syncities) that more accurately reflect urban development from 1900 to 1970. The analysis reveals how demographic shifts influenced the size and shape of cities, with implications for their economic performance and environmental quality. By employing instrumental variable regression and mediation analysis, this thesis identifies the causal pathways through which these spatial transformations affected income levels and air quality, both immediately following the migration and decades later. The findings highlight both economic growth and environmental challenges linked to urban expansion. Cities with larger and more dispersed urban forms benefited economically in the short term but faced greater environmental degradation over time. These results underscore the importance of urban spatial structure in shaping sustainable development trajectories. By bridging historical demographic changes with contemporary urban outcomes, this study offers valuable insights for urban planning and policy, demonstrating how historical conditions continue to shape modern challenges. This work also provides a methodological foundation for future research on the interplay between migration, urban form, and sustainability. This thesis is organized into seven chapters. Chapter 1 introduces the research goals and questions, explaining the importance of the study. Chapter 2 describes how the new urban spatial dataset was created and provides an overview of the key data. Chapter 3 looks at how urban areas in the U.S. changed between 1900 and 1970, providing background for the main analyses. Chapter 4 studies how the Great Migration affected the size and shape of cities, while Chapter 5 examines the economic and environmental effects of these changes. Chapter 6 explains how changes in urban areas connected the Great Migration to economic and environmental outcomes. Finally, Chapter 7 brings the findings together, discusses what they mean for policy, highlights limitations, and suggests ideas for future research. These chapters work together to show how the Great Migration reshaped American cities and what that means for sustainability today.