The Wall Street Journal has a somewhat interesting article about justice and fairness in checkout lines (“Justice — Wait for It — on the Checkout Line”, Aug 19th). While I believe someone writing under the title of “numbers guy” should adhere to higher standards (as I will discuss by the end of the posting), the article makes an interesting point:
“When it comes to customer satisfaction, time isn’t of the essence; fairness is. Many studies have shown how frustrating it is for customers to see others get served faster. Prof. Larson says the studies show customers will put up with waiting times up to twice as long to avoid such unfairness.”
I am not convinced that justice is more important than waiting time, but I agree with the overall tone of the article regarding the psychological (and pseudo-psychological) advantages of a single line (for more information you can check Larry David’s take in Curb Your Enthusiasm and my posting on additional operational advantages in this blog ).
While many organizations use a single line – many don’t and I think the most notable example for not using a single line is McDonald’s. One explanation of why supermarkets don’t use a single line (among admittedly many other reason) is the fact that with shopping carts it may be difficult to maneuver and see what cashier is available and the time to travel from the head of the line to the cashier is non-negligible. Whole foods store are using line directors for that purpose. However, you need enough volume to make that cost effective: The store in Columbus Circle is using a single line. The one in Evanston isn’t.
That brings me to the new word we learning today: “Faffing” – the terms is used to describe the wasted time when one customer gathers his or her belongings after completing checkout. People faff 3.17 seconds, on average (which means that in the grand scheme of things, faffing is a nice word to describe a negligible amount of time).
The article has an interesting figure on the average waiting time in lines for grocery stores in the major cities in the US. At first glance, the numbers seem unbelievable: the average waiting time in Washington DC is longer than 8 minutes while the average wait in St. Louis is 59 second. I am saying that “at first glance…”, because in a more careful look you realize that they are unbelievable. Period. I don’t believe them and neither should you. If you look at the fine print it says that this is based on a surveys of 1200 shoppers (which means that these are not actually waiting times, but impressions of time) and given the fact that there are 20 cities (more or less), we are talking about 60 shoppers per city. For those taking notes at home, I should say that, given the high variability among different shoppers (and stores), it is very likely that even if the waiting time distributions are identical in all cities, 60 shoppers will have, on average very poor (or very good) service.