By extending a typical endowment effect experiment with the possibility to win the endow-ment in a real effort contest, we found two enforcing effects that led to a complete market failure. Subjects who won the item in the competition had an extremely high willingness to accept (trophy effect)....

We conducted an experimental study on social preferences using dictator games similar to Fehr et al. (2008). We show that social preferences differ between participants who receive low-stakes monetary rewards for their decisions and participants who consider hypothetical stakes. The results are...