The Statistics Producers' Corner: Improved Estimates of Advance Monthly Retail Sales
Effective with the advance retail sales estimates for May 1996 (published in mid-June), the Census Bureau introduced a new sample and modified some of the statistical procedures used to estimate "advance" estimates of monthly retail sales. These improvements included the use of a new procedure to estimate nonemployer businesses, adoption of more efficient sample selection procedures, and real-location of businesses sampled by kind of business. Initial results indicated that the accuracy of advance estimates has improved in months since these changes were implemented, and research is underway to confirm the improvement.
The Census Bureau publishes advance estimates of retail sales within two weeks after each calendar month. The advance estimates are in current dollars, are seasonally adjusted, and feature totals for the United States, subtotals for durable and nondurable goods, and detail for sixteen kinds of retail business. These early estimates are based on "flash" reports from a small but representative sample of U.S. retail business.
Advance estimates are the first of three monthly retail sales estimates. "Preliminary" estimates are published about six weeks after each month, and "final" estimates are published after about ten weeks. Differences in successive estimates for the same month reflect the incorporation of reports from many more retailers and information more often drawn from actual business records. In addition, these monthly estimates, which are reported voluntarily, are subject to annual benchmark revisions based on data from mandatory annual surveys and quinquennial censuses.
One improvement was to change the procedure for estimating advance sales for nonemployer businesses (i.e., those with no paid employees) by adopting the same method used to estimate subsequent preliminary and final sales. This procedure attributes the month-to-month trend for businesses with employees to all retail businesses.(1) This method, which has been used in the full monthly retail survey since 1993, improves the consistency of sales of nonemployer businesses for all three monthly estimates. With the old sample, about 500 retail nonemployers, identified by a special "area" survey, were included in the monthly advance sample and their responses were used to develop estimates for nonemployers.
Another improvement was to increase advanced retail survey sampling efficiency so that the businesses selected for this survey are more likely to be actual participants. Under the new sampling procedures, businesses are not included in the advance retail mail survey if they have not responded to previous information requests. Excluding these businesses helps encourage higher levels of useful responses. …