They spent more than a year working and reworking the same basic idea: In order to explain the paradoxes that expected utility could not explain, and create a better theory to predict behavior, you had to inject psychology into the theory. By testing how people choose between various sure gains and gains that were merely probable, they traced the contours of regret. Which of the following two gifts do you prefer? Gift A: A lottery ticket that offers a 50 percent chance of winning $1,000 Gift B: A certain $400
