Recent Trends Around Zoning for Density

Calls for zoning reform have come increasingly from both sides of the political spectrum in recent years. While economists and libertarian political pundits have long criticized zoning for unnecessarily restricting housing supply in some of the United States' most economically prosperous regions, advocates for racial equity have also increasingly drawn attention to how certain exclusionary zoning tactics such as bans on attached housing and minimum lot sizes have upheld racial and class segregation. But to begin this work of reform, it is useful to ask: How has land use in major metropolitan areas already been shifting in recent decades?

Zoning Changes Analyzed in Metropolitan Areas

Rolf Pendall, Lydia Lo, and Jake Wegmann provide many insights into this question in their Journal of the American Planning Association article (Vol. 88, No. 1), "Shifts Toward the Extremes: Zoning Change in Major U.S. Metropolitan Areas From 2003 to 2019." In the article, the authors use data from the 2003 and 2019 instances of the National Longitudinal Land Use Survey (NLLUS) (the two most recent years that the survey has been collected) to see how the allowed densities in surveyed jurisdictions change over time.

They also combined this NLLUS data with demographic data from the 2013-2017 American Community Survey to better understand how zoning changes have corresponded with demographic makeup, particularly around race.

This work is in direct conversation with and aims to add nuance to Gyourko et al's 2019 article, "The Local Residential Land Use Regulatory Environment Across U.S. Housing Markets: Evidence From a New Wharton Index," which found a net increase in "regulatory restrictiveness" in zoning between 2008 and 2018 and that many metropolitan areas that were restrictive in 2008 had become even more restrictive in 2018. It also builds on Pendall and Wegmann's 2018 article in Housing Policy Debate with Jonathan Martin and Dehui Wei, "The Growth of Control? Changes in Local Land-Use Regulation in Major Metropolitan Areas From 1994 to 2003." This article looked at the changes in NLLUS data between the first time the survey was collected in 1994 and then in 2003, and found that land use solutions between these periods were being used to solve local problems more than they were being used to intentionally exclude new residents.

The authors make several important findings looking at the more recent 2003–2019 time period. First, they note that changes in land use regulations are bidirectional, rather than just trending towards more anti-density land use regimes (as economists often posit). You can see these changes in how many jurisdictions are upzoned or downzoned in Table 2. These changes, however, do vary geographically. The authors found that the most restrictive zoning in the United States in 2019, as well as shifts to make zoning more restrictive between 2003 and 2019, were concentrated in metropolitan areas in the Midwest and Northeast, while jurisdictions, where zoning accommodates multifamily housing, were concentrated on the West Coast and in Miami, Denver, and Washington, D.C.

Table 2: Change in maximum permitted density, repeat respondents, 2003–2019.

Figure 2: Maximum permitted density.

Zoning Changes Impact Density and Diversity

They also observed a general bifurcation of where jurisdictions fall on the spectrum of pro– to anti–density. Jurisdictions that only allowed low densities grew from 23 percent to 31 percent of repeat survey respondents between the two years, while jurisdictions that permitted higher densities grew from 21 percent to 28 percent (see Figure 2 from the article above).

The authors also affirmed past research showing that zoning that hinders multifamily development often has racially exclusionary impacts, whether intended or not. Using concentration indices that compared each responding jurisdiction's percentage of Black and Hispanic residents to its metro-area average in the mid-2010s, they found that the relationship between these two indices and the maximum permitted density in a jurisdiction was consistently positive. This means that jurisdictions with more restrictive zoning around density tend to have lower proportions of Black and Hispanic residents compared to their area average. After asking respondents whether a hypothetical 40-unit project would be allowed by right, with a special permit, or not at all within their jurisdiction, the proportion of Black and Hispanic residents was also highest within those jurisdictions that allowed the project by right. These findings are summarized in Figure 1 from the article below.

The article will help the reader to understand how nuanced changes in zoning have been in recent years and how varied they are across the United States, as well as how restrictive zoning still likely works to uphold segregated land use patterns.

Top Image: PhilAugustavo/iStock/gettyimages.com