Supplementary material from "Factors impacting effective altruism: Revisiting heuristics and biases in charity in a Replication Registered Report of Baron and Szymanska (2011)"

Individuals who donate to charity may be affected by various biases and donate inefficiently. In a replication and extension Registered Report with a US Amazon Mechanical Turk sample using CloudResearch (N=1403), we replicated Studies 1 to 4 in Baron and Szymanska (2011) with extensions on reputation and overhead funding. We found support for the effects of a preference for lower perceived waste (d=0.70[0.41,0.99]), lower past costs (d=0.59[0.16,1.02]), for the ingroup (d=0.52[0.47,0.58]), for having some diversification between charities (d=0.63[0.47,0.78] for single projects; d=1.18[1.00,1.36] for several projects versus one), and against forced charity (d=0.29[0.21,0.37]; nominally replicated, but has caveats regarding validity); as at least four of our five hypotheses were found to replicate, we conclude this as being a successful replication. Extending the replication, we found support for an unexpected preference for anonymity on donation allocation (opposite to our predictions; d=0.54[0.46,0.61]), and support for a preference towards paid-for overhead costs on donation allocation (d=0.60[0.52,0.68]). We discuss the implications and validity of these findings. All materials, data, and code were made available on: https://doi.org/10.17605/OSF.IO/BEP78. This Registered Report has been officially endorsed by Peer Community in Registered Reports: https://doi.org/10.24072/pci.rr.100775