of how it is characterized. Models assuming a purely intrinsic warm glow should report lesser warm glows than models also including extrinsic components. Empathy and the psychological determinants of warm glow The phenomenon of warm-glow giving was originally introduced as an economic model. It its original form, the warm-glow model lacked a satisfactory explanation for the underlying psychological processes. Early studies of warm glow were deliberately vague in attributing the experience to a cause. A more recent body of research has identified several important determinants of warm glow, including social distance, vividness to the beneficiary, and guilt avoidance. Taken together, these observations suggest the warm glow may be best described as the visceral manifestation of empathy. This is consistent with the moral psychological literature of empathy, most notably as advanced by Batson. In his "empathy-altruism hypothesis", Batson claims that empathy ("feeling sympathetic, compassionate, warm, softhearted, tender") evokes a desire for other-regarding behavior. Social distance Social distance is an important determinant of warm glow, particularly in the framework of empathy. Prior research has examined the link between emotional arousal and social distance, finding that mutual suffering and shared joy both increase as a function of social similarity. Consistent with the "identifiable victim effect", research has shown that people express a greater willingness to help when others are known, as opposed to statistical. Vividness to beneficiary While the vividness of the beneficiary is captured in social distance, the vividness to the beneficiary refers to a beneficiary's ability to perceive that kindness has been done upon them. As a determinant of warm glow, vividness to the beneficiary operates on two levels. The primary level concerns whether a beneficiary is aware that kindness has been given to them, absent any attribution of the source. The secondary level involves the identifiability of the benefactor. Warm glow should be positively impacted by both levels for vividness. Guilt Recent work has identified guilt avoidance as an important component of warm glow. Some have even compared guilt as the "flip side" of warm glow. Parameterizing guilt as a component of warm glow allows for deficit values of warm glow, which was originally constrained to strictly positive values in Andreoni (1989, 1990). In a recent publication, Andreoni and colleagues explain this by writing: "Psychologists posit that giving is initiated by a stimulus that elevates sympathy or empathy in the mind of the potential giver, much as the smell of