what is fair?

For the past 25 years experimental economists--of which I am one--have been infatuated with a pie-splitting problem known as the Ultimatum Game. Experimental economists are the hands-on tinkerers of my profession; where other economists attempt to build models from first principles, or extract empirical data from a messy universe, we build our own little universe out of volunteers and computers, and see how our theories work when real people get our hands on them. The Ultimatum Game is so popular because it is simple to explain and simple to run, yet its results involve one of the most complex problems of society: what are we saying when we say something is "fair"?

- Fair's fair