source for demographics data used by the Survey of Buying Power published annually by Sales and Marketing Management magazine. The Survey of Buying Power reports current data by metropolitan area, state, and region. Statistics such as retail sales by merchandise category, personal disposable income, and five-year projections are included in the survey. The BPI identifies these market factors and correlates them with the area's potential for these factors, and then combines the factors and their potential into a weighted index. The index is based on the area's share of the nation's disposable personal income, retail sales, and population.
Using the BPI, a manufacturer would look up a particular metropolitan area, state, or region to find out what percent of the nation's disposable income is in this market, along with the percent of the nation's retail sales and the percent of the nation's population. The buying power index for that particular area would then be calculated by multiplying each factor by a weighted value from a prescribed formula and then adding all three factors together. The result will tell the manufacturer the percentage of total national buying power in that particular area.
