Behavioral Economist and Harvard Business School Professor Michael Norton stopped by the Boston Public Radio studios Wednesday to discuss research from H.B.S. Doctoral Student Dafna Goor, on why consumers seem so enticed by the idea of exclusivity — perceived or otherwise.

Restaurants like Chipotle, Starbucks, and In-N-Out Burger all offer so-called “secret menu” options, which can typically be found on a restaurant’s website or smartphone app. At Starbucks, for example, there are nearly 40 additional drinks that patrons can order, from the "Apple Pie Frappuccino” to something called the “Black Eye."

"It seems like when consumers feel like they’re in the know, it makes them more likely to go, more likely to buy,” Norton said. "And this is the weird one — [they’re] more likely to tell other people about the place."

In some cases, companies aren’t even interested in keeping their secret items under wraps. At some restaurants, Norton said, they'll even put their secret options on full display.

“They’ll be on the menu, printed on the menu … 'secret burger,' which is really weird, because a secret shouldn’t be printed and available for everyone to see," said Norton. "So [Goor’s] initial idea was, just [by including] the word secret … you might actually enjoy it more.”

Michael Norton is the Harold M. Brierley professor of business administration at Harvard Business School. His Latest book is "Happy Money, The Science of Smarter Spending." He’s also co-host of the podcast "Talking Green," which explores the psychological forces that drive attitudes and decisions around money and investing.