Score contribution per author:
α: calibrated so average coauthorship-adjusted count equals average raw count
We disentangle the effects of choice (give vs. take) and externality (positive vs. negative) framing of decisions in isomorphic and payoff-equivalent experimental public good games. We find that, at the aggregate level, neither frame affects group contributions. At the individual level, the Take choice frame leads to greater free-riding, and also to somewhat higher contributions, i.e., to more extreme contribution behaviour.