Population projection accuracy: The impacts of sociodemographics, accessibility, land use, and neighbour characteristics

Population projection is essential to governments, businesses, and research communities for many purposes. Although projection performance is often evaluated, we know very little about what factors affect projection accuracy. It is important to understand these factors in order to utilise the projections knowledgeably. This study fills this gap in the literature by comprehensively investigating the possible factors associated with population projection accuracy in 2010 for the continental U.S. counties. The results indicate that the counties whose populations are more predictable tend to be desirable places—places with abundant employment opportunities, reliable public transportation infrastructure, easy access to work, and/or high land development potential; their neighbouring counties tend to have a well-educated population and a higher income level. Also, projection accuracy is highly spatially associated. The findings provide important insights for population projection users to understand the characteristics of counties and their neighbouring counties associated with their projection accuracy.