Until Later is Preferred Over Sooner : Multiplicity in Product Expiration Dates and Food Waste in Retail Stores

A food retailer incurs expiration waste (EW) at its store when a perishable product crosses its expiration date without being sold. One frequent scenario for EW occurrence is when units of a given product with multiple expiration dates are simultaneously available on store shelves. In such situations, a consumer is likely to purchase a later-to-expire unit, resulting in the EW of a sooner-to-expire unit. To mitigate the occurrence of such multiple-dates-led expiration waste (MDEW), retailers undertake a variety of interventions, including a price markdown of sooner-to-expire units and in-store inventory rotation. Most retailers, however, are often unaware of the extent of MDEW in their stores and, thus, are constrained in mitigating its generation.We provide the first large-scale evidence of the contribution of MDEW towards EW. We collaborate with a European retailer to compile a multi-category-multi-store dataset (~15.3 million sale transactions) on food products with three to 14 days of shelf-life. Across these products, at the product-store-week level, the sample average of the EW as the percentage of sales is 23%. To quantify MDEW’s contribution, we propose a novel methodology for computing its lower and upper bounds. In our retailer's context, on average, the MDEW's lower bound and upper bound equals 21% and 52% of the generated EW, respectively. Our study highlights MDEW's material share in generating EW; thus, it provides a solid premise for future in-depth academic investigation on MDEW management. Furthermore, to practitioners, it provides an immediately actionable methodology to measure MDEW in their store operations