Social discounting was measured as the amount of money a participant was willing to forgo to give a fixed amount (usually $75) to another person. In the first experiment, amount forgone was a hyperbolic function of the social distance between the giver and receiver. In the second experiment, degree of social discounting was an increasing function of reward magnitude whereas degree of delay discounting was a decreasing function of reward magnitude. In the third experiment, the shape of the function relating delayed rewards to equally valued immediate rewards for another person was predicted from individual delay and social discount functions. All in all, the studies show that the social discount function, like delay and probability discount functions, is hyperbolic in form.
Journal of Behavioral Decision Making
Rachlin, Howard; Jones, Bryan A (2008). Social Discounting and Delay Discounting. Journal of Behavioral Decision Making 21(1) 29-43. doi: 10.1002/BDM.567. Retrieved from https://oaks.kent.edu/psycpubs/121