This paper studies how imposing norms on contribution behavior affects individuals' intrinsic motivation. We consider … legally a tax. We design a randomized field experiment with treatments informing individuals that the levy is a tax. We …, communicating the legal norm results in a significant crowd-out of intrinsic motivation. In contrast, strongly intrinsically …

-interest, providing strong evidence for pocketbook voting. However, social preferences like altruism, public good considerations and …

strongly influence participation and voting. However, social or expressive motives, such as stated altruism, environmental …

the effects by income source can be explained by social norms. Our first experiment induces random variation in both … earned income and windfall bonuses and shows that only bonuses increases charitable donations. The second experiment uses an … elicited in the second experiment match the donation patterns in the first experiment both overall and across subject …