SUPERMARKET SHOPPING LISTS: THEIR EFFECT ON CONSUMER EXPENDITURE

The presence of a written shopping list on a major grocery buying trip to the supermarket is tangible evidence of out‐of‐store planning by the shopper. This pre‐planning may influence both time spent in store and grocery expenditure, two factors of importance to supermarket retailers. Set in a New Zealand city, examines the extent to which a written grocery shopping list affects these two factors by comparing the behaviour of two matched samples, one with lists and one without. The findings are conclusive: written shopping lists significantly reduce average expenditure; the presence of children accompanying the shopper significantly increases expenditure and time spent in store. While supermarket retailers cannot dissuade customers from bringing a written shopping list to the store, they can encourage customers to spend more time in‐store, and to shop with someone else, thereby increasing average expenditure.