We build on recent work analyzing consumers' ability to save by exploiting price dispersion in grocery stores. We show that store expensiveness is not universal but varies across consumers depending on the basket they consume. We incorporate this insight into a decomposition of price variance...

Quantity surcharges occur when retailers carry a product in two sizes and offer a promotion on the small size: the large size then costs more per unit than the small one. When quantity surcharges occur, sales of the large size decline only slightly even though the same quantity can be purchased...