This paper studies how imposing norms on contribution behavior affects individuals' intrinsic motivation. We consider the church levy, which the Catholic Church in Germany collects as a charitable donation, despite the fact that the levy is legally a tax. We design a randomized field experiment...

The motivation crowding effect suggests that an external intervention via monetary incentives or punishments may undermine (and under different indentifiable conditions strengthen) intrinsic motivation. As of today, the theoretical \lang1033 possibility of crowding effects is widely accepted...