Point at, nudge, or push private provisions to a public good? Field experimental evidence for experts, politicians, and nobodies


This paper investigates differences between a default, a recommendation, and a mandatory minimum contribution on private provision of a large scale public good (climate protection). Information on the regulator (neutral experimenter, expert or politician), its interaction with the intervention type, as well as with pre-intervention intrinsic motivation on voluntary contributions is analyzed. Data are from an online framed field experiment with a sample representative of the German internet using population. Main insights are: neither a recommendation nor a default close to the pre-intervention average change contributions; identifying the regulator reduces contributions when accompanying the recommendation, but not the default; contributions above the pre-intervention average are reduced by the default but increased by the mandatory minimum relative to the control; only the default negatively interacts with high intrinsic motivation; and regulator attributes neither interact with intrinsic motivation, nor with the type of intervention. The study contributes to the discussion of nudges as public policy instruments by comparing them to alternative interventions, i.e. pointing at or pushing contributions, and by shedding light on making the source of the intervention transparent.