Remember the Got Milk? campaign, with its cavalcade of famous people donning milk ‘staches to promote strong bones and the agricultural industry? Sure, Whoopi, I’ll drink some milk, you may have thought to yourself after seeing her poster. I’ll go get some right now! What those nefarious dairy farmers and Whoopi didn’t mention—we trusted you, Whoopi!—was that milk is always way in the back of the grocery store, along with other associated dairy products, past nearly every other item. Milk is on virtually every grocery list, so why is it located so far back there? Thankfully, someone stepped in to give a couple theories for milk’s inconvenient location.

On an episode of NPR’s Planet Money, host David Kestenbaum invited food writer and The Omnivore’s Dilemma author Michael Pollan to debate Russ Roberts, economist and EconTalk podcast host, on why one of the grocery store’s most popular items is usually positioned so far from the entrance and registers. Pollan is a fan of one of what would seem one of the more pervasive and obvious theories—that milk is in the back to manipulate customers into traversing past aisle after aisle of appetizing foods in the hopes that will pick up a few extra purchases along the way. The idea being, you come to the store for milk, pass through the candy aisle, go home with milk and Charleston Chews. 

“In one study, something like only a third of the items bought in the store were on the grocery list or planned for,” Pollan said.

Roberts argued for a more optimistic view of human nature, saying that milk is in the back to maximize freshness and shelf life as a courtesy to customers, whether we’re aware of it or not. The closer the milk is to the back, the shorter distance it has to travel between refrigerated storage units and their chilled shelving, thus keeping the liquid as cold as possible.

“I was told that for every degree of temperature it rises, it loses a day of being available and being sellable,” Roberts said. “…you and I want the milk in the back, even though it’s a little less convenient.”

To try getting to the bottom of all this, Kestenbaum interviewed a number of grocery store officials, asking them point blank why their milk is always housed at the ends of the earth. Their answer? Well, kind of both reasons, depending on who was asked.

In the end, it seems like milk is a gateway to the soul, a way to peer into the very nature of humanity like some lactose-laden Werner Herzog film. Are grocery chains manipulating customers into spending as much time and money in their stores as possible? Or are they working to keep our products as fresh as possible out of the goodness of their hearts? Is the glass of milk half-empty or half-full? Hobbes or Locke, man? That’s for you to decide in this great mystery we call life, my friend.