How the incentive to contribute affects contributions in the one-shot public goods game

Abstract

Enmeshed in various social structures, humans must often weigh their own interest against the interest of others—including the common interest of groups they belong to. The Public Goods Game (PGG), which succinctly pits individual interest against group interest, has been a staple of research into how people make such decisions. It has been studied in many variations, in the laboratory and (increasingly) online. One of the defining parameters of the PGG is the marginal per capita return of the group project (MPCR), which determines the incentive for contributing to the group project relative to the incentive of keeping points in the personal account. The effect of MPCR on contributions has been investigated before, but its effects have never been characterised with high resolution. Here, we present a systematic and high-resolution investigation of the effect of MPCR in groups of three. We do this in a large-scale online decision making experiment recruiting participants from Amazon Mechanical Turk. Our results provide a fine-grained account of the relationship between incentive to cooperate on the one hand and cooperation on the other, and can help to provide a basis for choosing MPCR magnitudes for future research endeavours using online PGG studies.

Equality and efficiency shape cooperation in multiple-public-goods provision problems.

“…The third contribution to psychological theory on cooperation is our finding that individuals often cooperated in an “opportunistic” way. By and large, our findings were in line with earlier work showing that individuals cooperate more when this creates outcome equality rather than inequality (Bagnoli & McKee, 1991; Buttrick & Oishi, 2017; Côté et al, 2015; Cozzolino, 2011; Fisher et al, 1995; Nikiforakis et al, 2012; Reuben & Riedl, 2009; Sommet et al, 2022) and when (personal) returns on investment are larger rather than smaller in absolute terms (Engelmann & Strobel, 2004; Gunnthorsdottir et al, 2007; Isaac & Walker, 1998; Komorita & Parks, 1995; Lugovskyy et al, 2017; van den Berg et al, 2020; R. Yu et al, 2014; Zelmer, 2003) and relative to fellow group members’ returns (Glöckner et al, 2011).…”

“…This conjecture contrasts with empirical findings that cooperation is common and frequent, even when it comes at a potential cost to individual interests (Kerr & Kaufman-Gilliland, 1994; Lojowska et al, 2023; Ostrom, 1998; Rand & Nowak, 2013; van Dijk & De Dreu, 2021; Van Lange, 1999; van Vugt & Hardy, 2009; Weber & Murnighan, 2008). In addition, experiments have revealed that larger rather than smaller returns from public goods (i.e., efficiency) further boost such cooperation (e.g., Engelmann & Strobel, 2004; Gunnthorsdottir et al, 2007; Isaac & Walker, 1998; Lugovskyy et al, 2017; Rapoport, 1967; Reuben & Riedl, 2013; van den Berg et al, 2020; Vlaev & Chater, 2006; C. Yu et al, 2009; Zelmer, 2003).…”

Social Learning Strategies and Cooperative Behaviour: Evidence of Payoff Bias, but Not Prestige or Conformity, in a Social Dilemma Game

“…A more likely explanation for the elevated contribution rate is the multiplication factor of 2 used in this experiment. High multiplication factors have been found to both raise cooperation rates and slow declines across rounds [87,88].…”

Spillover effects of competition outcome on future risky cooperation

“…However, it remains to be determined how competition outcome affects contestants' subsequent risky cooperative behavior with their previous opponents. Given that an increase in marginal return to an individual from contributions to the public good tends to enhance contributions [28][29][30] , it also remains unknown how variations in the marginal per-capita return (MPCR) for the PGG might modulate any behavioral change in contribution resulting from the outcome of the competitive experience and what the underlying psychological mechanism might be.…”