Urban planners are often suspicious of spontaneous order, associating it with chaos and anarchy. Though top-down design is indispensable for the construction of city infrastructure, it too often imposes excessive regulatory standards, which make housing unaffordable to the poor. In rapidly urbanizing countries, poor migrants from the countryside are especially hard hit. Subsidized housing provided to low-income households by governments rarely helps, as often this housing is too limited in scope.
Alain Bertaud

Read the working paper here. 
Listen to the podcast episode here.