The sales index measures nominal same-store sales, excluding restaurant and vehicle demand. The weekly index is statistically benchmarked to a broad-based monthly retail industry sales aggregate that currently represents about 75 retail chain stores, a tabulation also compiled by ICSC. A representative sample of those major retailers is used as a control group to extrapolate the weekly sales index, and so the weekly index represents industry sales statistically, and isn't just a sum of sales for a handful of retailers.

The week's drop in the index doesn't necessarily bode ill for sales throughout the rest of the season. "So far, this holiday season has been following the same shopping pattern as we experienced last year--a moderate start with softness the week following," said Michael Niemira, ICSC's chief economist and director of research. "It may very well mean that the consumer will step up their holiday shopping and spending over the upcoming weeks to finish the 2004 holiday season on the strong side." For December, ICSC expects sales to grow by 3.5% to 4.0%, on a year-over-year basis, Niemira added.

The results of an ICSC consumer-spending survey seem to bolster this argument. People still plan to do a lot of buying between now and Christmas. The ICSC-UBS ongoing holiday shopping survey, conducted between December 2 and 5, found that 32% of shoppers were more than half completed with holiday gift buying, up from 25% in the prior week. But still only 9% have totally completed their gift shopping.