This academic paper presents a simulation of urban neighbourhood formation and growth based on the economic theory of property rights.
The simulation shows that stable and efficient neighborhoods can evolve from a random distribution of "good" neighbors who offer voluntary reductions in the activities that reduce the welfare of neighbors. However, such neighbourhoods may not evolve and the city may fragment into inefficient neighborhoods in which the normal prisoner's dilemma dynamic holds; or into unstable neighborhoods. Which type of city emerges is purely a matter of chance and depends on the initial spatial distribution of good neighbors.
Thanks to Planning & Markets Editor
FULL STORY: Contractual Agreements And Neighbourhood Evolution

Trump Administration Could Effectively End Housing Voucher Program
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Planetizen Federal Action Tracker
A weekly monitor of how Trump’s orders and actions are impacting planners and planning in America.

Ken Jennings Launches Transit Web Series
The Jeopardy champ wants you to ride public transit.

Crime Continues to Drop on Philly, San Francisco Transit Systems
SEPTA and BART both saw significant declines in violent crime in the first quarter of 2025.

How South LA Green Spaces Power Community Health and Hope
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Sacramento Plans ‘Quick-Build’ Road Safety Projects
The city wants to accelerate small-scale safety improvements that use low-cost equipment to make an impact at dangerous intersections.
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