Rationality at Ralph's?

December 5, 2006
Posted by Jay Livingston

Sociologists are often accused of being preoccupied with the obvious and the useless. Business school faculty, by contrast, work on problems that have a practical payoff, right?

Somehow I got an the e-mailing list for a publication from the Wharton School of Business, which is to MBAs what MIT is to engineers. The latest issue has this article: “The ‘Traveling Salesman’ Goes Shopping: The Efficiency of Purchasing Patterns in the Grocery Store.” It asks if grocery shoppers plan out their route through the supermarket the way that sales reps plan a multi-city trip. “Do shoppers tend to be somewhat ‘optimal’ in their shopping patterns?” And it reaches the jaw-dropping conclusion: “travel inefficiency accounts for a large portion of the travel distance in the majority of grocery trips.”

I’ve shopped in supermarkets, and I’ve tagged along with others who shop in supermarkets. So this research seems right up there with “Ursine Defecation Patterns and Their Correlation with Sylvan Density Environmental Variables.” In a word, du-uhh.

The grocery researchers put Lojack-like transmitters on shopping carts so as to generate something like that map in Harry Potter with moving dots tracking people as they scamper around Hogwarts. Then the researchers matched the shopper’s path with the items scanned at the checkout. It’s an interesting high-tech “unobtrusive measure.” Without the shopper’s knowledge (I assume), they could know what items she bought and the route she took through the store. They also knew where those items were on the shelves, so they could work out the “ideal” route and compare it to the shopper’s actual route.

The high-tech research confirms what most of us could have guessed from our own experience, though it gives more precise estimates: Shoppers “spend only 20% to 30% of their time actually acquiring merchandise.”

O.K. People are not going from peanut butter to milk to ground chuck with tunnel-vision efficiency. (There’s a mid-Atlantic chain called ShopRite, and when I first saw that name I thought: exactly — shopping as ritual. And as Durkheim reminded us long ago, rituals are not about rationality and efficiency.)

But if people spend only 30% of their time actually “shopping,” what are they doing the other 70% of the time?

Most likely, they’re looking. As they’d probably tell you, they’re looking at all the stuff — that’s why companies spend so much on packaging and why they compete so desperately for eye-level locations on the shelves. But my guess is that shoppers also spend a fair amount of time looking at the other shoppers. And that is something they would probably not tell you.

I don’t mean that people would deliberately lie about what they are doing. It’s just that they are not aware of it, and more important, nobody thinks of people-watching as part of shopping. If you asked me what I did at the ShopRite, it just wouldn’t occur to me to say that I saw a lot of different people.

If only there were an unobtrusive Lojack that could monitor not just where shoppers are pushing their carts but what they are looking at. Failing that, we might see if shoppers traveled more efficiently when the store was relatively empty and there was nobody to look at. Or maybe some clever students who still need an idea for a research project could figure out some other way.