 Writing a column in the Journal of Economic Perspectives under the title "Anomalies", Thaler wrote features on the many ways observed economic behavior in markets deviated from theory.One such anomaly was the endowment effect by which individual preferences are framed based on reference positions (Kahneman et al., 1990).In an experiment in which one group was given a mug and the other was asked how much they were willingness to pay (WTP) for the mug, it was found that the price that those endowed with the mug where willingness to accept (WTA) greatly exceeded that of the WTP.