A quick scan of the article makes me want to say "more evidence needed before we can conclude much": they ran two studies, one on 50 Stanford students, one on 400 Mechanical Turkers. Neither seems to provide very strong evidence to me about how people might make giving decisions in the real world since the study conditions feel pretty far to me to what actual giving decision feel like. Here's the setup of the two studies from the paper:

Study 1 involves data from 50 Stanford University undergraduate students in April 2014 who made a series of binary decisions between money for charities and/or money for themselves. In addition to receiving a $20 completion fee, participants knew that one of their decisions would be randomly selected to count for payment.14 The design and results for Study 1 are detailed below (and see Online Appendix B.1 for instructions and screenshots).

Three types of charities are involved in Study 1. The first charity type involves three Make-A-Wish Foundation state chapters that vary according to their program expense rates, or percentages of their budgets spent directly on their programs and services (i.e., not spent on overhead costs): the New Hampshire chapter (90%), the Rhode Island chapter (80%), and the Maine chapter (71%).15 The second charity type involves three Knowledge Is Power Program (KIPP) charter schools that vary according to college matriculation rates among their students who completed the eighth grade: Chicago (92%), Philadelphia (74%), and Denver (61%).16 The third charity type involves three Bay Area animal shelters that vary according to their live release rates: the San Francisco SPCA (97%), the Humane Society of Silicon Valley (82%), and the San Jose Animal Care and Services (66%).

And the second one:

Study 2 involves data from 400 Amazon Mechanical Turk workers in January 2018 who made five decisions about how much money to keep for themselves or to instead donate to the Make-A-Wish Foundation.32 In addition to receiving a $1 completion fee, participants knew that one of their decisions would be randomly selected to count for payment.33 Relative to Study 1, Study 2 allows for a test of excuse-driven responses to charity performance metrics on a larger sample and via an identification strategy that does not require a normalization procedure. The design and results for Study 2 are detailed below (and see Online Appendix B.4 for instructions and screenshots).