Similar to Levati and Neugebauer (2001), a clock is used by which participants can vary their individual contributions for voluntarily providing a public good. As time goes by, participants either in(de)crease their contribution gradually or keep it constant. Groups of two poorly and two richly...

We study whether selection affects motivation. In our experiment subjects first answer a personality questionnaire. They then play a 3-person game. One of the three players decides between an outside option assigning him a positive amount, but leaving the two others empty-handed and allowing one...