Putting a premium on altruism: A social discounting experiment with South African university students

This paper reports on a social discounting experiment conducted with university students in South Africa. In line with other social discounting task experiments, participants identify target individuals at different degrees of intimacy in their social network and then make 10 choices involving sums of money for themselves or their targets. For an altruism premium to exist, senders’ donations to recipients should be positive, statistically and economically significant, and independent of relationship closeness. We hypothesize that in addition to the altruism premium for kin documented in the literature, there may be other premia for family in general and for partners and friends. We find that, apart from the “kinship” premium, there is a sizeable “intimacy” premium, which together translates into a substantial “family” premium. The study also finds a “friendship premium”, as is documented in various experiments. The closeness of relationships among family and kin, especially close kin, has a significant and large effect on altruism. The results also attest to the importance of the extended family in regards to the “kinship” premium on altruism. These various premiums on altruism emphasise the importance of the supportive role of various social systems. Nevertheless, altruism within families and among close kin might also be enhanced by building more cohesive and stronger families using developmental social welfare programmes.本论文报告了一项针对南非大学生开展的社会折扣（social discounting）实验研究。与其他社会折扣任务（social discounting task）实验范式一致，受试者需从自身社交网络中识别出亲密度各异的目标个体，随后完成10项涉及为自身或目标个体分配金额的选择任务。若要存在利他溢价（altruism premium），捐赠者对受赠者的捐赠金额需为正值，且在统计学与经济学层面均具有显著性，同时与双方关系亲疏无关。我们提出假设：除已有文献中记载的亲属利他溢价外，普通家庭成员、伴侣及朋友群体或同样存在利他溢价。研究结果显示，除“亲属溢价（kinship premium）”外，还存在显著的“亲密度溢价（intimacy premium）”，二者叠加可形成可观的“家庭溢价”。本研究同时发现了“友谊溢价（friendship premium）”，这与多项已发表实验的研究结果相符。家庭成员与亲属之间的关系亲疏，尤其是近亲之间的关系亲密度，对利他行为具有显著且强烈的影响。研究结果亦证实了扩展家庭（extended family）在利他行为的“亲属溢价”效应中所发挥的重要作用。上述各类利他溢价凸显了各类社会支持体系的重要性。尽管如此，通过发展型社会福利项目构建更具凝聚力、更为稳固的家庭，亦可强化家庭内部与近亲之间的利他行为。