By Victoria Morckel (University of Michigan-Flint) and Noah Durst (Michigan State University)
Sophisticated methods for studying changes in the physical forms of cities that are losing population (i.e. “shrinking cities”) are lacking in the literature. This research highlights the use of a newer method—ArcGIS Pro’s emerging hot spot analysis of space-time cubes from defined locations—to examine the spread of housing vacancy, a common indicator of city shrinkage. The method has existed in ESRI’s ArcGIS Pro since 2017, but has not been previously applied to the study of vacancy. This method differs from traditional hot spot methodologies in that it identifies statistically significant spatiotemporal relationships (i.e. spatial change over time).
We use the method to examine the spread of vacancy, at the census tract level, from 2012-2019 in Ohio’s seven largest metropolitan statistical areas (MSAs). The outputs categorize census tracts as follows: no spatial pattern (i.e. not statistically significant), low vacancy rates that decreased over time (“intensifying cold”), low vacancy rates that were stable over time (“persistent cold”), low vacancy rates that increased over time (“diminishing cold”), high vacancy rates that decreased over time (“diminishing hot”), high vacancy rates that were stable over time (“persistent hot”) and high vacancy rates that increased over time (“intensifying hot”).
Results: We found variation in the extent and location of vacancy spread within and between Ohio MSAs. In alignment with prior literature, vacancy spread was most pronounced in central cities, particularly in shrinking cities located within shrinking MSAs. However, unlike prior literature that presumes a relatively uniform spread of vacancy from a cluster of vacant housing units, we showed that many Ohio MSAs concurrently experienced spread, contraction, and vacancy stabilization in tracts located adjacent to, or within close proximity of, one another. These results indicate that how vacancy proliferates is not solely a matter of geographic determinism, whereby high vacancy in one tract predicts high vacancy in neighboring tracts in future years.
Additionally, we investigated the relationship between vacancy and population change. We compared the emerging hot spot categories’ levels of population change, then considered how spatial patterns at the MSA level differ by the interaction of city-wide and MSA population trends. We found a probable relationship between vacancy spread at a small scale (the census tract) and population dynamics at much larger geographic scales (the city and MSA). As such, the results run counter to much of the housing literature that theorizes vacancy as a neighborhood-level phenomenon, and further suggests that initiatives intended to reduce vacancy (e.g. foreclosure prevention programs, demolition funding) should account for population trends in adjacent neighborhoods, the city as a whole, and the MSA—not just physical conditions within a particular neighborhood.
Victoria Morckel is an associate professor of urban planning and public policy at the University of Michigan’s Flint campus. She is also a member of the American Institute of Certified Planners (AICP). Her research addresses ways to improve quality of life in deindustrialized cities in the Midwestern United States, with an emphasis on issues like property vacancy, blight, and neighborhood change.
Noah J. Durst is an assistant professor of urban and regional planning in the School of Planning, Design and Construction at Michigan State University. His research interests include housing, urban informality, spatial mismatches in housing and employment, and municipal annexation.