Even though you know that giving makes people happier, you do not know that telling this to people makes them happier. It may decrease that effect.
Furthermore, when money are involved, statements are generally considered as information with regards to the value of the cause, and by promising such rewards you may well make yourself look more dubious to a wide audience, which would depend very strongly on the specific wording—so an experiment may find the effect negative, when it could be positive with other wording, and vice versa.
Plus you will undermine the point of those who give in part because they need to demonstrate certain degree of selflessness in a way that would be suboptimal for selfish people to fake (honest signalling).
edit: specifically, at least some partially selfish agents seem to follow this overall principle (hypothetical figures for the illustrative purposes): 1000$ is 1 unit of utility when spent on myself or close family members, but 0.6 units of utility when spent on distant charitable causes, plus perhaps 0.6 units of utility from the improvements in cooperation enabled by this demonstration that the utility of lives of other people, while smaller than that of oneself and own family, are nonzero for you (gains in cooperation enabled by e.g. others knowing for sure that you won’t take $1000 causing total of $10 000 in damage even when it is legal for you to do so). Note that a perfectly selfish party would not accept this deal. Of course one can’t actually reason like this explicitly in the real life—if you do value other people’s lives, you want that positive quality to be visible, as a part of general heuristic.
Even though you know that giving makes people happier, you do not know that telling this to people makes them happier. It may decrease that effect.
Indeed, this is probably my most major concern. For a person versed in cognitive biases, it might seem fairly plausible that our own intuitions about what makes us most happy would be flawed and that the research on the relationship between charitable giving and happiness would be worth taking seriously. But to the average person, suggesting that they engage in charitable giving because it will make them happier is an invitation to assess it as an option on relative to other ways they could spend their money on their own happiness, where charitable giving would probably lose.
Even though you know that giving makes people happier, you do not know that telling this to people makes them happier. It may decrease that effect.
Furthermore, when money are involved, statements are generally considered as information with regards to the value of the cause, and by promising such rewards you may well make yourself look more dubious to a wide audience, which would depend very strongly on the specific wording—so an experiment may find the effect negative, when it could be positive with other wording, and vice versa.
Plus you will undermine the point of those who give in part because they need to demonstrate certain degree of selflessness in a way that would be suboptimal for selfish people to fake (honest signalling).
edit: specifically, at least some partially selfish agents seem to follow this overall principle (hypothetical figures for the illustrative purposes): 1000$ is 1 unit of utility when spent on myself or close family members, but 0.6 units of utility when spent on distant charitable causes, plus perhaps 0.6 units of utility from the improvements in cooperation enabled by this demonstration that the utility of lives of other people, while smaller than that of oneself and own family, are nonzero for you (gains in cooperation enabled by e.g. others knowing for sure that you won’t take $1000 causing total of $10 000 in damage even when it is legal for you to do so). Note that a perfectly selfish party would not accept this deal. Of course one can’t actually reason like this explicitly in the real life—if you do value other people’s lives, you want that positive quality to be visible, as a part of general heuristic.
Indeed, this is probably my most major concern. For a person versed in cognitive biases, it might seem fairly plausible that our own intuitions about what makes us most happy would be flawed and that the research on the relationship between charitable giving and happiness would be worth taking seriously. But to the average person, suggesting that they engage in charitable giving because it will make them happier is an invitation to assess it as an option on relative to other ways they could spend their money on their own happiness, where charitable giving would probably lose.