Rectangular Cartons and Cylindrical Cans

You may sometimes get baffled by the random questions asked by your toddlers while strolling at the park, or buying groceries at the supermarket. You wonder how these seemingly simple questions are a little hard to explain. You should thank Robert H. Frank, a professor of Economics at Cornell University who seemed to have found sound and simple explanations to your children's inquiries. His explanations are contained in his book, The Economic Naturalist. I will try to devote a few entries on this fascinatingly relevant information.

Why is milk sold in rectangular cartons, while soft drinks are sold in round cans?

Frank offers a number of possible explanations for this:

1. Soft drinks are directly consumed from the container while milk isn't. Cylindrical cans fit more comfortably in hand while drinking.
2. Rectangular containers save shelf space. The shelf space they save counts much more in the case of milk than in soft drinks. Soft drinks can be stored in open shelves that cost less and with little (or no) operating expense. Milk, on the other hand, must be stored under a strictly regulated low temperature (to prevent spoilage). A specially made shelf then must be used to keep its freshness. These shelves cost more than an average one and always incur a bigger operating cost. Thus, every inch a pack of milk occupies is worth more than that of a soft drink can and must be maximized hence the rectangular cartons which practically fill every available space when arranged side by side.