We replicate Andreoni (Quarterly Journal of Economics 110: 1–21, 1995)’s finding that agents behave more selfishly when taking from a public account than when giving to a public good. Based on a neutral language setting we add new insights into motivations to give or take in a linear public good setting: we find that Andreoni’s result is partly driven by the complete elimination of giving options in the taking frame. However, a pure extension of the action space into the taking domain also leads to a significant increase in selfish behavior.

Does competition affect moral behavior? This fundamental question has been debated among leading scholars for centuries, and more recently, it has been tested in experimental studies yielding a body of rather inconclusive empirical evidence. A potential source of ambivalent empirical results on the same hypothesis is design heterogeneity—variation in true effect sizes across various reasonable experimental research protocols. To provide further evidence on whether competition affects moral behavior and to examine whether the generalizability of a single experimental study is jeopardized by design heterogeneity, we invited independent research teams to contribute experimental designs to a crowd-sourced project. In a large-scale online data collection, 18,123 experimental participants were randomly allocated to 45 randomly selected experimental designs out of 95 submitted designs. We find a small adverse effect of competition on moral behavior in a meta-analysis of the pooled data. The crowd-sourced design of our study allows for a clean identification and estimation of the variation in effect sizes above and beyond what could be expected due to sampling variance. We find substantial design heterogeneity—estimated to be about 1.6 times as large as the average standard error of effect size estimates of the 45 research designs—indicating that the informativeness and generalizability of results based on a single experimental design are limited. Drawing strong conclusions about the underlying hypotheses in the presence of substantive design heterogeneity requires moving toward much larger data collections on various experimental designs testing the same hypothesis.

This paper investigates two channels of prosociality: indirect reciprocity and charitable giving. We conducted a natural field experiment in a hair salon in Hamburg, Germany, over the course of four months. In the baseline, we collected data on customers’ tips—a scenario absent indirect reciprocity and donations. In two treatments we had the hairdresser collect donations to a charity. In one treatment the hairdresser pointed out the opportunity to donate. Our data indicate that the voluntary activity of collecting donations in the salon led to greater tips for the hairdresser and significant donations. In the second treatment, the hairdresser unconditionally donated to the charity before the customers could. This donation did not increase tips further compared with the collection-only treatment. Our data indicate that indirect reciprocity works in the field. We find evidence that indirect reciprocity and charitable giving work as complements. Data, as supplemental material, are available at http://dx.doi.org/10.1287/mnsc.2016.2519 . This paper was accepted by Uri Gneezy, behavioral economics.