Complex and diverse supply chains help cities by making them resistant to sudden supply chain shocks, according to a recently published paper from researchers at Pennsylvania State University,

“We found that complexity can be a good thing,” said Alfonso Mejia, the paper’s corresponding author and an associate professor of civil and environmental engineering at Penn State. “Cities with diverse supply chains — sources from a broad range of domestic and global suppliers — appear to be better protected against shocks, and experience less-intense shortages. Large cities like New York and Chicago, just by being large and having less dependency on specific supply partners, are less affected by supply chain interruptions. But medium cities are hurt by a lack of diversity when sourcing the supplies they need.” 

The researchers were able to determine that medium-sized cities, in particular, experienced less intense supply chain shocks, on average, when they increased supplier diversity. They said the potential benefits of supply chain complexity would be most evident in cities that had populations between 100,000 and 500,000.They also found that the intensity of supply chain shocks experienced by cities sharply decreased when they had a larger relative network of supply chains. 

The research paper, entitled “Cities can benefit from complex supply chains,” was published in the Urban Sustainability section of the Nature Partner Journals series on Nature.com. The paper analyzed a large dataset of more than 1 million annual supply flows to 69 major U.S. cities between 2012 and 2015.

It was co-authored by Mejia, Michael Gomez (a postdoctoral researcher at Penn State) and Nazlı Barçın Doğan (a former Penn State graduate student). Support for the research paper was provided by Penn State University, the National Science Foundation and The Ministry of National Education of Turkey.