Michael Lynn is a professor of services marketing at the Cornell Hotel School. A former busboy, bartender, and waiter, he began studying tipping 40 years ago as a psychology graduate student and has now published over 80 scientific papers on the topic. His research and/or opinions on tipping have been covered by numerous media outlets, including the Economist, Financial Times, Forbes, International Herald Tribune, NY Times, Wall Street Journal, Washington Post, Freakonomics Radio Podcast, ABC’s 20/20, CNN’s Money Matters, and NPR’s All Things Considered, Planet Money, and Morning Edition.