Cities in the U.S. use zoning codes to regulate land use. They can mandate the type of constructions allowed on a piece of land through these regulations. Often, that leads to neighborhoods exclusive to single-family homes. [1] While city planning necessitates some land regulation (no one should build residential homes next to a chemical plant, etc), strict zoning codes in many U.S. cities today are harmful. These regulations have detrimental effects on housing affordability, racial justice, and economic prosperity. Strict zoning codes decrease housing affordability. The prevalence of single-family zones mandates low density in some of the most popular cities in the United States. This under-utilization of land leads to fewer new houses constructed and thus depressed supply of housing. Consequently, zoning codes and other land regulations correlate strongly with elevated housing prices. They likely bear responsibility for these high prices. [2] Moreover, strict zoning codes often encourage owners of high-end houses to expand or renovate their properties. These practices can further elevate the values of the housing market without increasing the supply of it. [3] Therefore, strict zoning codes depress housing affordability in multiple ways and make expensive cities more expensive. Strict zoning codes have a particularly deterrent effect on African Americans. Ever since the 20th century, cities have used zoning codes to explicitly or implicitly enforce racial segregation. The protection of single-family zones often shuts African Americans out of comfortable living conditions and sufficient resources. As a result, African Americans of all income levels are more likely to live next to pollution sources and develop health conditions. [4] The segregation of neighborhoods also perpetuates the segregation of schools. As a result, racially segregated schools tend to deliver fewer resources to black children and other children of other minority groups. [5] Thus, strict zoning codes have long hindered the process of racial equity. Strict zoning codes also hurt the macro-economy. Due to the low densities, cities often fail to realize their full economic potential. Some of the most expensive cities, such as New York or San Francisco, are also the most productive places with significant economic activities. However, the lack of affordable housing has discouraged many potential skilled residents. When not all productive laborers can fit in productive places for an artificial reason, the labor market has an inefficient equilibrium. This mismatch has prevented potential economic growth. According to one estimate, the strict zoning codes in three cities (New York, San Jose, and San Francisco) have restricted about a 10% growth of the U.S. economy. [6] Strict zoning codes protect single-family houses at the expense of housing availability, racial justice, and national economic growth. For these reasons, it is a harmful policy. [1]. Badger, Emily. 2018. "The Bipartisan Cry Of ‘Not In My Backyard’", , 2018. https://www.nytimes.com/2018/08/21/upshot/home-ownership-nimby-bipartisan.html. [2]. Glaeser, Edward L., and Joseph E. Gyourko. 2002. "The Impact Of Zoning On Housing Affordability". SSRN Electronic Journal. doi:10.2139/ssrn.302388. [3]. Schuetz, Jenny. 2019. "Restrictive Zoning Is Impeding DC’S Goal To Build More Housing". The Avenue. The Brookings Institute. https://www.brookings.edu/blog/the-avenue/2019/10/08/restrictive-zoning-is-impeding-dcs-goal-to-build-more-housing/. [4]. Brennan, Maya, Emily Peiffer, and Kimberly Burrowes. 2019. "How Zoning Shapes Our Lives". Housing Matters. https://housingmatters.urban.org/articles/how-zoning-shapes-our-lives. [5]. Rothwell, Jonathan. 2012. "Housing Costs, Zoning, And Access To High-Scoring Schools". The Brookings Institute. https://www.brookings.edu/wp-content/uploads/2016/06/0419_school_inequality_rothwell.pdf. [6]. Hsieh, Chang-Tai, and Enrico Moretti. 2019. "Housing Constraints And Spatial Misallocation". American Economic Journal: Macroeconomics 11 (2): 1-39. doi:10.1257/mac.20170388.