Using the Juster Scale to Estimate the Demand-Price Relationship

Abstract

The Juster scale was used to estimate the price-demand relationship for two branded products, Coca-Cola in cans, and Campbell's Red and White Label soup. For each product predictions were obtained of the number of items that would be purchased, during the following four weeks, at each of two hypothetical prices, one above and one below the current retail price. Predictions were obtained using two variations on the Juster procedure: the multiple question method and the constant sum method. Actual numbers purchased were obtained in follow-up interviews. Actual purchases of Coca-Cola were almost exactly at the predicted level, but purchases of the soup brand were less than a third of those predicted. This is the first reported use of the Juster Scale to predict purchases of brands as opposed to products, or to estimate price-demand relationships.