Shared rewarding overcomes defection traps in generalized volunteer's dilemmas

Abstract

For societies to produce or safeguard public goods, costly voluntary contributions are often required. From the perspective of each individual, however, it is advantageous not to volunteer such contributions, in the hope that other individuals will carry the associated costs. This conflict can be modeled as a volunteer's dilemma. To encourage rational individuals to make voluntary contributions, a government or other social organizations can offer rewards, to be shared among the volunteers. Here we apply such shared rewarding to the generalized -person volunteer's dilemma, in which a threshold number of volunteers is required for producing the public good. By means of theoretical and numerical analyses, we show that without shared rewarding only two evolutionary outcomes are possible: full defection or coexistence of volunteers and non-volunteers. We show that already small rewards destabilize full defection, stabilizing small fractions of volunteers instead. Furthermore, at these intermediate reward levels, we find a hysteresis effect such that increasing or decreasing group sizes can trigger different social outcomes. In particular, when group size is increased, the fraction of volunteers first increases gradually before jumping up abruptly; when group size is then decreased again, the fraction of volunteers not only remains high, but even continues to increase. As the shared reward is increased beyond a critical level, the bistablitity underlying this hysteresis effect vanishes altogether, and only a single social outcome remains, corresponding to the stable coexistence of volunteers and non-volunteers. We find that this critical level of shared rewarding is relatively small compared to the total cost of contributing to the public good. These results show that the introduction of shared rewarding is remarkably effective in overcoming defection traps in the generalized volunteer's dilemma.

Cooperation and coordination across cultures and contexts: Individual, sociocultural, and contextual factors jointly influence decision making in the volunteer's dilemma game

“…Consequently, attempts to artificially produce prosocial norm spillovers in a purely lab‐based setting (e.g., Peysakhovich & Rand, ) cannot tell us much about the extent to which cultural and societal norms are internalized by individuals in the real world (Galizzi & Navarro‐Martínez, ). Finally, our results suggest that many social and cultural incentives that sustain volunteering (Chen et al, ), such as favorable public recognition and associated feelings of pride, are not fully internalized, and are therefore “fragile” in the sense that they require continuous usage and perhaps lack of anonymity, in order to remain effective. In the absence of explicit social structures and reputational concerns that prevent deviations from societal norms, individuals from highly cooperative cultures (e.g., Bali) are no more prosocial than participants from relatively individualistic Western cultures (e.g., England).…”

“…Beyond economics and game theory, the VDG has also been used to explain the evolution of volunteering in a society (Chen, Gross, & Dieckmann, ; He, Wang, & Li, ; Myatt & Wallace, ), the vigilance behavior of prey animals (Archetti, ), and the functional dynamics of viruses, bacteria, amoeba, and yeast (Archetti, ). The VDG also relates to the social psychological literature on the diffusion of responsibility (also known as the “bystander effect”; Darley & Latané, ; Latané & Darley, , ; Latané & Rodin, ; for a more recent review and meta‐analysis see Fischer et al, ), whereby people are less likely to help a person in need of assistance (e.g., someone injured and calling for help) if others around them did not react to the incident.…”

The evolution of anti-social rewarding and its countermeasures in public goods games

“…While most theoretical and empirical studies focused on incentive systems where sanctions or rewards are administered by peers [11,[13][14][15][16][17][18][19][20][21][22][23][24], it is only recently that scholars have started to investigate mechanisms that can be viewed as primitive institutions, namely 'pool' mechanisms [25][26][27][28][29][30][31]. The idea is that individuals can decide to pool their effort and provision an incentive fund before contributing to the PGG.…”

Optimal distribution of incentives for public cooperation in heterogeneous interaction environments

“…Recently, ample research efforts have been devoted to the study of the emergence of institutions and their effectiveness in promoting prosocial behavior (Yamagishi, 1986; Ostrom, 1990; Gurerk et al, 2006; Henrich, 2006; Cuesta et al, 2008; Sigmund et al, 2010; Baldassarri and Grossman, 2011; Sasaki and Unemi, 2011; Szolnoki et al, 2011a,b; Cressman et al, 2012; Isakov and Rand, 2012; Sasaki et al, 2012; Bechtel and Scheve, 2013; Cressman et al, 2013; Vasconcelos et al, 2013; Vukov et al, 2013). It has been shown, for example, that institutional rewarding promotes the evolution of cooperation in the liner public goods game (Cuesta et al, 2008), the nonlinear public goods games (Chen et al, 2013), and in structured populations in general (Jiménez et al, 2008, 2009; Szolnoki et al, 2011a,b). However, institutional punishment is less costly and thus more effective to warrant a given level of public cooperation, especially if participation in the public goods game is optional (Sasaki et al, 2012; Sasaki, 2013).…”

“…Surprisingly, few studies have thus far considered the problem of the optimal allocation of incentives for maximizing public cooperation. Traditionally, all groups and all individuals are considered equal, and depending on their strategies thus deserved of the same reward or punishment (Jiménez et al, 2008; Sasaki et al, 2012; Chen et al, 2013). This simple assumption, however, does not agree with the fact that in social networks individuals have different roles, which depend significantly on the degree of the node that they occupy.…”