new paper out of UCLA, published this month in the Journal of the American Planning Association, explores the link between land-use regulation and the segregation of income groups in metropolitan areas, and contains a number of insights that should be of interest to policymakers and stakeholders in the development industry.

Citing established links between neighbourhood social mix and the improved physical, economic, and social health of community members, authors Michael Lens and Paavo Monkkonen set out to investigate how zoning and development regulation exacerbates the segregation of various income groups.

The authors identify two primary culprits: density restrictions, which tend to result in high-wealth enclaves, and the concentration of zoning and development control at the local level, which tends to isolate poor and working-class families.

Density restrictions may take many forms, from square-footage minimums, to floor-space ratio maximums, to restrictive definitions of single-family housing, but in all cases represent what the authors describe as “barriers to housing opportunity”. These barriers result in proverbial ‘walled-cities’, in which wealth is highly-concentrated and lower income groups are excluded.

Similarly, localized regulation of zoning and development is found to be strongly linked with income segregation. The authors point to political pressure from local interests (i.e. NIMBYism) and a multiplicity of zoning and project approval requirements as being strongly correlated with the segregation of low-income households. Where zoning and development regulation are centralized at the State level, the study finds that income segregation is significantly decreased.

These findings suggest that British Columbia’s current transition to a new Building Act, which standardizes building and construction regulation across the province and streamlines the zoning and project approval process, is a step in the right direction. But the paper raises two further insights that suggest municipal authorities (particularly the City of Vancouver, where the new Building Act will not apply) should be evaluating their density restriction policies if they want to meaningfully address income inequality in their communities.

Firstly, the authors note that inclusionary housing policies (e.g., the introduction of affordable, multi-family housing into wealthier, low-density neighbourhoods) are more effective at addressing income segregation than policies aimed at gentrifying low-income urban areas.

Second, the authors note that municipal bodies, by virtue of their limited legislative capacity, typically lack the means to address income inequality issues in a direct way. The deregulation of density controls and the streamlining of approval processes are two matters over which local governments exercise significant control, and thereby have the potential to tangibly impact income inequality and segregation in their communities.