Pizza-makers can't very well stop buying cheese, he says; but they can buy less: "When cheese is cheap, they offer cheesy pizzas. Even the crust is stuffed with cheese." When high milk prices make cheese more expensive, consumers can be steered in a different direction. "Maybe now you'll see more chunky vegetable pizzas," he speculates.
Likewise Starbucks, he says, can't stop making lattes; "but they could sell more flavored coffees—ones that don't involve milk."