Free Predictably Irrational by Dr. Dan Ariely Page A

is not just another price, it turns out. Zero is an emotional hot button—a source of irrational excitement. Would you buy something if it were discounted from 50 cents to 20 cents? Maybe. Would you buy it if it were discounted from 50 cents to two cents? Maybe. Would you grab it if it were discounted from 50 cents to zero? You bet!
    What is it about zero cost that we find so irresistible? Why does FREE ! make us so happy? After all, FREE ! can lead us into trouble: things that we would never consider purchasing become incredibly appealing as soon as they are FREE ! For instance, have you ever gathered up free pencils, key chains, and notepads at a conference, even though you’d have to carry them home and would only throw most of them away? Have you ever stood in line for a very long time (too long), just to get a free cone of Ben and Jerry’s ice cream? Or have you bought two of a product that you wouldn’t have chosen in the first place, just to get the third one for free?
    Z ERO HAS HAD a long history. The Babylonians invented the concept of zero; the ancient Greeks debated it in lofty terms (how could something be nothing?); the ancient Indian scholar Pingala paired zero with the numeral 1 to get double digits; and both the Mayans and the Romans made zero part of their numeral systems. But zero really found its place about AD 498, when the Indian astronomer Aryabhata sat up in bed one morning and exclaimed, “Sthanam sthanam dasa gunam” —which translates, roughly, as “Place to place in 10 times in value.” With that, the idea of decimal-based place-value notation was born. Now zero was on a roll: It spread to the Arab world, where it flourished; crossed the Iberian Peninsula to Europe (thanks to the Spanish Moors); got some tweaking from the Italians; and eventually sailed the Atlantic to the New World, where zero ultimately found plenty of employment (together with the digit 1) in a place called Silicon Valley.
    So much for a brief recounting of the history of zero. But the concept of zero applied to money is less clearly understood. In fact, I don’t think it even has a history. Nonetheless, FREE ! has huge implications, extending not only to discount prices and promotions, but also to how FREE ! can be used to help us make decisions that would benefit ourselves and society.
    If FREE ! were a virus or a subatomic particle, I might use an electron microscope to probe the object under the lens, stain it with different compounds to reveal its nature, or somehow slice it apart to reveal its inner composition. In behavioral economics we use a different instrument, however, one that allows us to slow down human behavior and examine it frame by frame, as it unfolds. As you have undoubtedly guessed by now, this procedure is called an experiment.
    I N ONE EXPERIMENT, Kristina Shampanier (a PhD student at MIT), Nina Mazar (a professor at the University of Toronto), and I went into the chocolate business. Well, sort of. We set up a table at a large public building and offered two kinds of chocolates—Lindt truffles and Hershey’s Kisses. There was a large sign above our table that read, “One chocolate per customer.” Once the potential customers stepped closer, they could see the two types of chocolate and their prices. *
    For those of you who are not chocolate connoisseurs, Lindt is produced by a Swiss firm that has been blending fine cocoas for 160 years. Lindt’s chocolate truffles are particularly prized—exquisitely creamy and just about irresistible. They cost about 30 cents each when we buy them in bulk. Hershey’s Kisses, on the other hand, are good little chocolates, but let’s face it, they are rather ordinary: Hershey cranks out 80 million Kisses a day. In Hershey, Pennsylvania, even the streetlamps are made in the shape of the ubiquitous Hershey’s Kiss.
    So what happened when the “customers” flocked to our table? When we set the