In 2016 Auckland implemented zoning reforms that allowed for increased density. Three subsequent studies found the upzoning resulted in increased housing supply and reduced rents. However, the findings were challenged by economists Cameron Murray and Tim Helm and these critiques have been cited in formal planning and policy processes.

This working paper responds to Murray and Helm, finding their critiques lack merit, misinterpret the methodologies, and rely on unsuitable data analysis. The authors address concerns regarding sample selection, the distinction between building consents and completions, and the econometric models used. 

Ultimately, the paper concludes there is remarkably robust evidence that zoning reforms increased housing supply and reduced rents in Auckland; and Auckland’s reforms should be a model for other cities.

Key findings

• Murray and Helm misunderstand the methodologies used in the original studies, particularly concerning the selection of control groups and the interpretation of linear trends in the data.
• The original studies demonstrate the robustness of their findings through various sensitivity tests.
• Murray and Helm employ inappropriate data transformations which lead to misleading conclusions.
• The original studies confirm a common finding in economic literature that is accepted by a large majority of economists.
• Being unfounded, the criticism by Murray and Helm should not be permitted to influence policy discussions.