Growing pains in local food systems: a longitudinal social network analysis on local food marketing in Baltimore County, Maryland and Chester County, Pennsylvania

Local food systems are growing, and little is known about how the constellation of farms and markets change over time. We trace the evolution of two local food systems (Baltimore County, Maryland and Chester County, Pennsylvania) over six years, including a dataset of over 2690 market connections (edges) between 1520 locations (nodes). Longitudinal social network analysis reveals how the architecture, actor network centrality, magnitude, and spatiality of these supply chains shifted during the 2012-2018 time period. Our findings demonstrate that, despite growth in the number of farmers' markets, grocery stores, farms and restaurants in both counties, each local food system also experienced high turnover rates. Over 80% of the market connections changed during the study period. Farms, farmers' markets, and grocery stores showed a 40-50% 'survival' rate, indicating their role in sustaining local food systems over longer time periods. Other actors, such as restaurants, had a much higher turnover rate within the network. Both food systems became more close-knit and consolidated as the center of gravity for both local food systems pulled away from urban areas toward rural farmland. Evidence of both growth and decay within local food systems provides a new understanding of the social networks behind local food markets.

Automated summary

This study traced the evolution of two local food systems in Maryland and Pennsylvania over six years, revealing high turnover rates despite growth in the number of market connections between locations. The survival rate of farms, farmers' markets, and grocery stores was around 40-50%, indicating their crucial role in sustaining local food systems. The networks of local food systems became more close-knit and consolidated, with the center of gravity shifting towards rural farmland.