On a cold January day when our older son was five years old, he came into the house with an ice-covered rock, probably a small piece of cement. He asked me, "Daddy, would you buy this for ten cents?" I said no, that was too much money for this particular rock. He then said, "Maybe you'll buy it for five cents." I said yes. Even though the rock was really ugly, I was pleased that our five-year-old son understood that demand curves slope downward and was willing to cut his price to sell his product.
Economics Is Everywhere