Score contribution per author:
α: calibrated so average coauthorship-adjusted count equals average raw count
In many contexts people can choose how many charities to help. This paper presents results from a laboratory experiment that varies whether the subjects have a choice in the number of charities to donate to and whether they are given an option to opt out. We find that the choice increases donation frequency, but does not influence donation amounts. If the choice also includes the opt-out option, there is no increase in the donation frequency or amount.