Trying Harder and Doing Worse: How Grocery Shoppers Track In-Store Spending

Although almost one in three U.S. households shops on a budget, it remains unclear whether and how shoppers track their in-store spending to stay within those budgets. A field study and two laboratory studies offer four key generalizations about budget shoppers in grocery stores: (1) They predominantly use mental computation strategies to track their in-store spending, (2) they adapt their mental computation strategy to the dominant range of price endings of items in their shopping baskets, (3) those who try to calculate the exact total price of their basket are less accurate than those who estimate the approximate price, and (4) motivated shoppers are less accurate than less motivated shoppers (because they tend to calculate rather than estimate the total basket price). A second field study demonstrates that shoppers who underestimate the total price of their basket are more likely to overspend, leading to negative store satisfaction.