For those who do not know, the Consumer Price Index is a way of tracking how much your cash will buy. As such, it provides an indication of inflation, at least as it is felt by the average individual buyer. It is calculated by assembling a “market basket” of items that people buy, and then tracking the price of thousands of such items to determine how the price is changing in different sectors and in different regions and metropolitan areas. It perhaps sounds boring, but it really is pretty interesting to watch and to try to predict.
Anyway, the market basket is adjusted fairly continuously to try to map the mean buying habits of Americans. This may work at the broader level, but what about changes at the micro-level? What do those changes tell us about the bridge between economic and social behavior. Admittedly, this USA Today article on the trends detected on Ebay doesn’t ask some of these bigger questions so much as hint at them. Interesting stuff. The question always remains: how indicative is eBay of the wider group of purchasers. These sorts of questions (how much do heavy users of the internet reflect the larger society) will continue to bother social scientists much longer than they bother marketers, I suspect.