Mapping Regional Disparities in Discounted Grocery Products

TL;DR

This study analyzes geographic variations in retail promotion of near-expiry food products in Denmark, revealing regional differences in product types and sale frequency, emphasizing the need for tailored sustainability strategies.

Contribution

It introduces a dual-clustering and bipartite network approach to map regional disparities in retail promotion of near-expiry foods, highlighting spatial relationships and their impact on food waste.

Findings

Rural stores sell meat and dairy products up to 2.2 times more frequently.

Metropolitan areas favor convenience products with less environmental impact.

Regional retail dynamics influence food waste reduction strategies.

Abstract

Food waste represents a major challenge to global climate resilience, accounting for almost 10% of annual greenhouse gas emissions. The retail sector is a critical player, mediating product flows between producers and consumers, where supply chain inefficiencies can shape which items are put on sale. Yet how these dynamics vary across geographic contexts remains largely unexplored. Here, we analyze data from Denmark's largest retail group on near-expiry products put on sale. We uncover the geospatial variations using a dual-clustering approach. We characterize multi-scale spatial relationships in retail organization by correlating store clustering -- measured using shortest-path distances along the street network -- with product clustering based on promotion co-occurrence patterns. Using a bipartite network approach, we identify three regional store clusters, and use percolation thresholds to corroborate the scale of their spatial separation. We find that stores in rural communities put meat and dairy products on sale up to 2.2 times more frequently than metropolitan areas. In contrast, metropolitan and capital regions lean toward convenience products, which have more balanced nutritional profiles but less favorable environmental impacts. By linking geographic context to retail inventory, we provide evidence that reducing food waste requires interventions tailored to local retail dynamics, highlighting the importance of region-specific sustainability strategies.