Although prices in most retail outlets are set by the retailer, this does not mean that these prices ________________________. On any particular day we find that all products have a specific price ticket on them. However, this price may be different from day to day or week to week. The price that the farmer gets from the wholesaler is much more flexible from day to day than the price that the retailer charges consumers. If, for example, bad weather leads to a poor potato crop, then the price that supermarkets have to pay to their wholesalers for potatoes will go up and this will be reflected in the prices they mark on potatoes in their stores. Thus, these prices do reflect the interaction of demand and supply in the wider marketplace for potatoes. Although they do not change in the supermarket from hour to hour to reflect local variations in demand and supply, they do change over time to reflect the underlying conditions of the overall production of and demand for the goods in question.