Presentation on theme: "A Comparison of Prices at Food City and Kroger Justin A. Grieves, Byron H. Smith, Amy F. Szczepański, and Joseph R. H. White."— Presentation transcript:
A Comparison of Prices at Food City and Kroger Justin A. Grieves, Byron H. Smith, Amy F. Szczepański, and Joseph R. H. White
Comparisons Made in Phase 3 Grieves: various grocery items for price-conscious shopper (only collected unit price data) Smith: beverage items Szczepański: food items eligible for WIC White: various grocery items
Primary Comparison: Logarithm of Price Ratio Logarithm of Kroger price / Food City Price Can conclude mean < 0 with p = 0.04 (t-test) Can conclude mean < 0 with p = 0.006 (Signed-Rank test)
Recommendations Kroger is cheaper overall for shoppers who shop the entire store. Kroger is cheaper for shoppers who are looking for the cheapest prices overall and do not care about whether the product is generic or not. Wilcoxon Signed Rank Test: 95% confident that median price is between 0% and 5% less at Kroger.
Issue that Made a Difference Looking at a wide range of items made a difference. With beverages only, there was no statistically significant difference between the two stores. Wilcoxon Signed Rank: p = 0.5830
Finding Percentage Saved log ratio of items cheaper at Kroger log ratio of items cheaper at Food City BC a confidence interval 80.2% – 87.6%83.3% – 90% Bootstrap used to find confidence interval for median. Kroger price is 80.2% – 87.6% FC priceFC price is 80.2% – 87.6% Kroger price
Summary Among our selected items, prices were on average cheaper at Kroger Shop at Kroger if shopping for variety of items and don’t care about name brands. Looking at a variety of items got statistically significant results when only beverages did not. By shopping wisely at both stores, shoppers could save up to 17% – 20%.