We investigate the leading motivations for indirect reciprocity by experimentally studying the role of type-based, intentions-based, and outcome-based preferences. We design a novel experimental setting in which participants can help other participants under varying probability of being seen by third parties. Those third-party observers can then reward participants based on both their history of helpful behavior and the observability of that behavior. Because good deeds done in public are often strategically motivated to build reputation, while only truly altruistic people help in private, we can identify whether indirect reciprocity is directed towards good deeds or good people. We find that indirect reciprocity towards an individual is influenced by their previous attempts to be helpful and their impact on others, but is surprisingly unaffected by the authenticity of past benevolent actions. That is, good deeds are rewarded regardless of whether these actions reflect true altruism or are likely a strategic play to encourage future reciprocal kindness. We discuss implications for theories of indirect reciprocity and sustained cooperation in large groups.

I propose a framework of competing motivations that suggests a weak incentive can diminish the appeal of a strong incentive. This occurs when their motivations interfere with one another, rather than simply adding up. Consequently, combining a strong and weak incentive scheme can be less effective than offering the strong incentive alone. I demonstrate this in two pre-registered experiments on MTurk CloudResearch (N = 2,517). In the first study, participants completed effort tasks incentivized with monetary rewards, charitable rewards, or both. Those motivated solely by monetary rewards completed 23% more tasks than participants offered the same monetary reward paired with a charitable incentive. In the second study, participants completed tasks incentivized with monetary rewards, a chance to win a gift card, or both. Participants offered both incentives did not perform better than those offered only monetary rewards; when accounting for heterogeneity in preferences for the gift card incentive, the combined incentive scheme resulted in significantly fewer tasks completed compared to those working only for monetary rewards. These findings support the competing motivations hypothesis and underscore the need to reconsider the conventional additive approach to incentive design.

When interacting with someone, their prior behavior towards us and others comprise their reputation, affecting our willingness to reciprocate. Yet, most research on reciprocity has largely examined direct and indirect reciprocity in isolation. We address this gap with a large-scale online experiment in which Reciprocators observed two one-shot decisions by a matched Helper—one affecting themselves and one affecting an anonymous third party—and then chose whether to help that same Helper. By controlling for the distribution of monetary payoffs and the Helper’s expectation of reciprocation, our design cleanly isolates the influence of direct versus indirect reciprocity when both are present. We find that although both forms of interaction drive reciprocation, direct reciprocity carries roughly twice as much weight as indirect reciprocity. These results cannot be fully explained by any existing model of reciprocity, underscoring the need for an integrated framework to understand reciprocal behavior in broader contexts. 

This field experiment investigates the effect of volunteering on future donation behaviour, aiming to understand if volunteering and donating are substitutes or complements.

I investigate the interplay between the inherent cost of a prosocial activity and the feelings of personal satisfaction (often termed "warm glow") that arise from engaging in such behaviours. Using a 2×2 experimental design, participants are divided into groups working either 'for themselves' or 'for charity', undergoing tasks that are either 'easy' or 'hard'. The study is designed to test the hypothesis that participants working for charity will experience greater warm glow when they work on more difficult tasks.