Allocating Housing Change to Small Geographies: A Synthesis of Census, HCD, and Survey Results in California

Keywords: HCD, DOF, Census, Housing Change, Small Areas, Demography
Abstract Type: Poster Abstract

Abstract

The California Department of Finance (DoF) produces annual housing estimates at city and county scale, and produces smaller regional estimates by request for administrative areas ill-represented by city boundaries. Because of the aggregate nature of inputs to city estimates, dasymetric techniques using open-source data are necessary. Starting in 2023, the Census Bureau has published annual block-level housing counts, reflective of snapshot totals within the Master Address File. This dataset is updated from the postal service among other secondary sources and is under constant revision for geographic correction. Compared with the annual DoF Housing Unit Survey and Housing and Community Development (HCD) Annual Project Report certificates of completion, this work aims to assess the feasibility of combining Census Address Counts with additional data for determining block-level locations of housing unit change in California. Overlap was found among all datasets, however, HCD captured more genuine change whereas Census data showed greater evidence of geographic correction than new construction / demolitions. No single dataset was found to sufficiently explain total housing change as submitted by cities and counties in the Housing Unit Survey. In conclusion, a method synthesizing all datasets is proposed as an interim method of identifying housing change within small geographies.