Score contribution per author:
α: calibrated so average coauthorship-adjusted count equals average raw count
We study experimentally the effect of personality traits on the willingness to make and keep a promise to volunteer. In our experiment, Amazon Mechanical Turk participants were given the option to volunteer by donating time and effort to a charity. They also answered a series of questionnaires, including the Big Five personality test and attitudinal questions that we used to construct an index representing altruistic self-concept. Self-concept refers to the way we describe and evaluate ourselves. We find that altruistic self-concept mediates how personality affects volunteering decisions. In particular, agreeableness has a strong influence on the probability of making and keeping promises to volunteer through its effect on altruistic self-concept. Our findings have useful implications for non-profit organizations.