If a previously unpaid activity (donating blood) is paid then we often observe that this activity is reduced. In this paper, it is hypothesised that the price offered is taken as a proxy for the "market value" of the activity. Depending on how the actor valued the activity previously,...

In the Solidarity Game (Selten and Ockenfels, 1998), two "rich" persons can support a "poor" one. A strong positive correlation between one rich person's solidarity contribution and his expected contribution of the other is observed. This paper investigates the causality behind this correlation....

Bargaining results emerge from the interplay of strategic options and social preferences. For every bargaining game, however, the advantage of a player having certain preferences in terms of negotiated equilibrium revenues might differ. We explore the hypothesis that preferences change according...