Urban Reconstruction and Population Redistribution: Evidence from Tokyo after the Great Kanto Earthquake

2026-07-03

AI Summary

This study investigates the drivers of post-disaster population redistribution in Tokyo following the 1923 Great Kantō Earthquake, with a focus on the relative roles of reconstruction policies and market forces. Leveraging digitized historical census data and exploiting exogenous variation in district-level fire damage, the analysis combines econometric regression with spatial methods to show that land readjustment policies reduced residential space and elevated rents, leading to persistent population decline in heavily affected areas. Although multi-story housing reconstruction offset losses in dwelling area, low-income households increasingly resorted to housing sharing as a coping mechanism against high rents, generating a countervailing effect between population outflow and retention. The findings demonstrate that market-driven price mechanisms—not institutional zoning—predominantly shaped post-disaster population distribution, highlighting the critical buffering role of housing sharing in urban recovery.

Abstract

This study examines the impact of the 1923 Great Kanto Earthquake on population distribution within Tokyo City. The earthquake triggered massive fires that devastated nearly half of the city, including much of its urban core. To investigate its consequences, I digitized systematic census statistics and conducted regression analyses using variation in fire damage across areas. The results show that land readjustment implemented as part of the reconstruction project reduced residential land area within the burned area, leading to higher unit rents. Although the total residential floor area eventually recovered through the construction of multi-story dwellings, the population of the burned area remained below its pre-earthquake level throughout the period examined. In addition, the zoning system established before the earthquake had little effect on population redistribution. These findings suggest that post-disaster population distribution was shaped primarily by market-based price adjustments rather than institutional regulations. The analysis further shows that rising rents reduced the number of kinship households while increasing incentives for workers to rent rooms as lodgers. The rent burden borne by lodgers, relative to that borne by landlords, was lower in the burned area, making housing sharing an effective response. Overall, the post-disaster population decline in the burned area reflected the net effect of two opposing forces: population loss driven by rising rents and population retention through increased housing sharing among worker households seeking to mitigate those rent increases.

Problem

• urban reconstruction
• population redistribution
• Great Kanto Earthquake
• rent adjustment
• housing sharing

Innovation

• land readjustment
• rent adjustment
• housing sharing
• population redistribution
• post-disaster reconstruction