Zoning density regulations results in segregation by wealth

Zoning regulations on density contributes to segregation of wealthy neighborhoods but not poor neighborhoods. The more complex zoning approval processes contribute to segregation in poor neighborhoods.

Mobile home housing in Stronach Township
Mobile home housing in Stronach Township

It is assumed that zoning, through minimum parcel and dwelling sizes, helps cause segregation of people and families by income. But there has been little scientific research on this subject. A recent research project examined 95 of the largest cities in the United States and confirms that density zoning regulations are associated with segregation of people based on middle and upper income groups.

But the study finds that density regulations in zoning do not have the same segregation result with poor households. The study also found that there is pressure at the local government level to regulate land use linked to higher rates of income. But more state government control is connected to lower-income segregation.

The study mentioned is “Do Strict Land Use Regulations Make Metropolitan Areas More Segregated by Income?” and was published in the Journal of the American Planning Association (Winter 2016, Vo. 82, No. 1, page 6+) by Michael Lenz and Paavo Monkkonen, assistant professors of urban planning at University of California, Los Angeles.

Lenz and Monkkonen point out that segregation of the rich is growing rapidly in the United States where there tends to be an abundance of resources and amenities and a disproportionate amount of political power.  Conversely, the segregation of poor people is happening in areas with high crime and limitations in schooling, employment, health and upward mobility. This affluence and poverty concentration is more so than it has been in the past four decades in United States metropolitan areas. Both authors also argue that local economies require diversity to be more successful.

But the question raised is, how much zoning contributes to this segregation? The conclusions from this study are that land use regulation does affect income segregation, but not equally. The findings are:

  • The more local planning is exacerbates the tendency to segregate by income.
  • The more pressure from local interest groups on residential development exacerbates the tendency to segregate by income.
  • When state government has more power over land use decision-making, there is less lower-income segregation.
  • Density restrictions lead to segregation of affluent into their own neighborhoods but do not appear to have the same affect for segregation of poor into their own neighborhoods.
  • The complexity of the process for zoning approvals (measured by counting the number of approvals required for one project) is strongly related to segregation of low-income households.

The study drew these conclusions from looking at 95 of the largest metropolitan areas in the United States, using state-of-the-art measures on land use regulation and income segregation. The results of Lenz and Monkkonen’s work should be of interest to planners seeking to reduce income segregation. For example, poor people are a locally unwanted land use, so local zoning authorities put up barriers. Where the state steps in and exerts control you have less discrimination. To counter income segregation, there should be a better balance between state governments or regional, power and local control in zoning decisions. Density restrictions should be relaxed – perhaps through the use of form based zoning and encouragement of the “missing middle” forms of housing. Also, use of inclusionary housing or inclusionary zoning can be an effective tool to bring work force housing into areas of higher-income.

Those in Michigan State University Extension that focus on land use provide various training programs on planning and zoning topics mentioned here. They are available to be presented in your county. Contact your local land use educator for more information.

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