Discounting one selected item or the whole cart?Velkavrh, Žiga (Avtor) customer behaviourdecision theorynormative benchmarkper-purchase discountper-selected-item discountThe article addresses two real-world decision-making problems faced by customers who are offered two mutually exclusive supermarket discount formats: an unconditional per-selected-item discount and a conditional per-purchase discount applicable only when the total purchase amount reaches a specified spending threshold. The analysis provides a normative benchmark for comparing these formats from the customer's perspective and determines what a customer should do, once they have selected their cart, to minimise total payment. When the threshold is reached, the problem reduces to a monetary comparison between applying a higher discount to a most expensive item in the cart and applying a lower discount to the overall purchase. When the threshold is not reached, the problem becomes more complex, as the analysis requires determining whether applying a higher discount to a most expensive item in the original cart results in a lower or higher total payment than adding an additional item to reach the threshold and applying a lower discount to the new total purchase amount. To automate the required calculations and thereby facilitate discount comparisons, we provide a prototype decision aid in the form of R functions, which could serve as a basis for supermarket decision-support tools.20262026-08-14 09:59:58Članek v reviji23479UDK: 519.816ISSN pri članku: 2590-2911DOI: 10.1016/j.ssaho.2026.103435COBISS.SI-ID: 287789059sl