scholarly journals Extinction times in diffusive public good population dynamics

2018 ◽  
Author(s):  
Gregory J. Kimmel ◽  
Philip Gerlee ◽  
Philipp M. Altrock
Keyword(s):  
Growth Rate ◽  
Public Goods ◽  
Public Good ◽  
Evolutionary Dynamics ◽  
Tragedy Of The Commons ◽  
Free Rider ◽  
Extinction Time ◽  
Free Riders ◽  
Time To Extinction ◽  
The Commons

AbstractThe co-evolutionary dynamics of competing populations can be strongly affected by frequency-dependent selection and population structure in space. As co-evolving populations grow into a spatial domain, their initial spatial arrangement, as well as their growth rate differences determine the dynamics. Here, we are interested in the dynamics of producers and free-rider co-evolution in the context of an ecological public good that is produced by a sub-population but evokes growth benefits to all individuals. We consider the spatial growth dynamics in one, two and three dimensions by modeling producer cell, free-rider cell and public good densities in space, driven by birth, death and diffusion. Typically, one population goes extinct. We find that uncorrelated initial spatial structures do not influence the time to extinction in comparison to the well-mixed system. We derive a slow manifold solution in order to estimate the time to extinction of either free-riders or producers. For invading populations, i.e. for populations that are initially highly segregated, we observe a traveling wave, whose speed can be calculated to improve the extinction time estimate by a simple superposition of the two times. Our results show that local effects of spatial dynamics evolve independently of the dynamics of the mean populations. Our considerations provide quantitative predictions for the transient dynamics of cooperative traits under pressure of extinction, and a potential experiment to derive elusive details of the fitness function of an ecological public goods game through extinction time observations.Author SummaryEcological public goods (PG) relationships emerge in growing cellular populations, for example between bacteria and cancer cells. We study the eco-evolutionary dynamics of a PG in populations that grow in space. In our model, public good-producer cells and free-rider cells can grow according to their own birth and death rates. Co-evolution occurs due to public good-driven surplus in the intrinsic growth rates and a cost to producers. A net growth rate benefit to free-riders leads to the well-known tragedy of the commons in which producers go extinct. What is often omitted from discussions is the time scale on which this extinction can occur, especially in spatial populations. We derive analytical estimates of the time to extinction in different spatial settings, and identify spatial scenarios in which extinction takes long enough such that the tragedy of the commons never occurs within the lifetime of the populations. Using numerical simulations we analyze the deviations from analytical predictions. Our results have direct implications for inferring ecological public good game properties from in vitro and in vivo experimental observations.

scholarly journals Shame and honour drive cooperation

2011 ◽  
Vol 7 (6) ◽  
pp. 899-901 ◽  
Author(s):  
Jennifer Jacquet ◽  
Christoph Hauert ◽  
Arne Traulsen ◽  
Manfred Milinski
Keyword(s):  
Public Goods ◽  
Public Good ◽  
Tragedy Of The Commons ◽  
Experimental Paradigm ◽  
The Public ◽  
Common Resources ◽  
Public Goods Experiments ◽  
The Commons

Can the threat of being shamed or the prospect of being honoured lead to greater cooperation? We test this hypothesis with anonymous six-player public goods experiments, an experimental paradigm used to investigate problems related to overusing common resources. We instructed the players that the two individuals who were least generous after 10 rounds would be exposed to the group. As the natural antithesis, we also test the effects of honour by revealing the identities of the two players who were most generous. The non-monetary, reputational effects induced by shame and honour each led to approximately 50 per cent higher donations to the public good when compared with the control, demonstrating that both shame and honour can drive cooperation and can help alleviate the tragedy of the commons.

scholarly journals The Non-Tragedy of the Non-Linear Commons

2020 ◽  
Author(s):  
Marco Archetti ◽  
István Scheuring ◽  
Douglas Yu
Keyword(s):  
Spatial Structure ◽  
Public Goods ◽  
Public Good ◽  
Social Interactions ◽  
Empirical Evidence ◽  
The Public ◽  
Free Riders ◽  
Individual Contributions ◽  
The Commons ◽  
Biological Hierarchy

Public goods are produced at all levels of the biological hierarchy, from the secretion of diffusible molecules by cells to social interactions in humans. However, the cooperation needed to produce public goods is vulnerable to exploitation by free-riders — the Tragedy of the Commons. The dominant solution to this problem of collective action is that some form of positive assortment (due to kinship or spatial structure) or of enforcement (reward and punishment) is necessary for public-goods cooperation to evolve. However, these solutions are only needed when individual contributions to the public good accrue linearly, and the assumption of linearity is never true in biology. We explain how cooperation for nonlinearpublic goods is maintained endogenously and does not require positive assortment or enforcement, and we review the considerable empirical evidence for the existence and maintenance of nonlinear public goods in biology. We argue that it is time to move beyond discussions about assortment and enforcement in the study of cooperation in biology.

scholarly journals Bringing tax avoiders to light: moral framing and shaming in a public goods experiment

2021 ◽  
pp. 1-24
Author(s):  
Stefanos A. Tsikas
Keyword(s):  
Public Goods ◽  
Public Good ◽  
Social Dilemmas ◽  
Tax Avoidance ◽  
Social Contagion ◽  
Public Goods Game ◽  
Free Riders ◽  
Social Sanctions ◽  
Moral Framing ◽  
Public Goods Experiment

Abstract With a linear public goods game played in six different variants, this article studies two channels that might moderate social dilemmas and increase cooperation without using pecuniary incentives: moral framing and shaming. We find that cooperation is increased when noncontributing to a public good is framed as morally debatable and socially harmful tax avoidance, while the mere description of a tax context has no effect. However, without social sanctions in place, cooperation quickly deteriorates due to social contagion. We find ‘shaming’ free-riders by disclosing their misdemeanor to act as a strong social sanction, irrespective of the context in which it is applied. Moralizing tax avoidance significantly reinforces shaming, compared with a simple tax context.

Developers, Quality Control and Download Volume in Open Source Software (OSS) Projects

2017 ◽  
Vol 29 (2) ◽  
pp. 43-66
Author(s):  
Geoffrey Hill ◽  
Pratim Datta ◽  
Candice Vander Weerdt
Keyword(s):  
Quality Control ◽  
Public Good ◽  
Open Source ◽  
Open Source Software ◽  
Inflection Point ◽  
Returns To Scale ◽  
Tragedy Of The Commons ◽  
Curvilinear Relationship ◽  
Segmented Regression ◽  
The Commons

The open-source software (OSS) movement is often analogized as a commons, where products are developed by and consumed in an open community. However, does a larger commons automatically beget success or does the phenomenon fall prey to the tragedy of the commons? This research forwards and empirically investigates the curvilinear relationship between developers and OSS project quality and a project's download volume. Using segmented regression on over 12,000 SourceForge OSS projects, findings suggest an inflection point in the number of contributing developers on download volume – suggesting increasing and diminishing returns to scale from adding developers to OSS projects. Findings support the economic principle of the tragedy of the commons, a concept where an over-allocated (large number) of developers, even in an open-source environment, can lead to resource mismanagement and reduce the benefit of a public good, i.e. the OSS project.

scholarly journals INSTRUMEN EKONOMI ATAU PRIVATISASI PENGELOLAAN LINGKUNGAN? KOMENTAR ATAS RUU JASA LINGKUNGAN

2008 ◽  
Vol 38 (4) ◽  
pp. 602
Author(s):  
Andri Gunawan Wibisana
Keyword(s):  
Public Goods ◽  
Natural Resources ◽  
Tragedy Of The Commons ◽  
Environmental Services ◽  
Charge System ◽  
User Charge ◽  
The Commons ◽  
Funds Management

AbstrakIndonesia 's Regional Representatives Board is planning to submit a Bill onenvironmental services. The Bill proposes the establishment of a newinstitution in managing environmental service fund, which is collectedthrough a user-charge system. This new institution is expected to be anindependent Commission of Environmental Funds Management, of whichcommissioners are responsible only to the President. The author finds thatthe spirit of the Bill has nothing to do with the needs to implement economicinstruments in terms of user charge. Instead, the Bill stems from the needs toprivatize public goods such as environmental services. The spirit can be seenin the forms of reference to Hardin's "the Tragedy of the Commons ", inwhich public goods are considered a form of inefficiency in the allocation ofresources that will eventually lead to the overexploitation of the goods. Inaddition, the spirit of privatization can also be seen in the Bill's proposal tohand over the tasks of the Commission, which include planning, execution,and monitoring, to private entities. The author argues that, with such spiritof privatization in the management of natural resources, the Bill is actuallyinconstitutional, and hence, should be rejected.

scholarly journals Plasticity facilitates sustainable growth in the commons

2013 ◽  
Vol 10 (81) ◽  
pp. 20121006 ◽  
Author(s):  
Matteo Cavaliere ◽  
Juan F. Poyatos
Keyword(s):  
Public Good ◽  
Small Groups ◽  
Sustainable Management ◽  
Sustainable Growth ◽  
Effective Strategy ◽  
Ecological Constraints ◽  
The Public ◽  
Free Riders ◽  
The Commons ◽  
Minimal Effort

In the commons, communities whose growth depends on public good, individuals often rely on surprisingly simple strategies, or heuristics, to decide whether to contribute to the shared resource (at risk of exploitation by free-riders). Although this appears a limitation, we show here how four heuristics lead to sustainable growth when coupled to specific ecological constraints. The two simplest ones—contribute permanently or switch stochastically between contributing or not—are first shown to bring sustainability when the public good efficiently promotes growth. If efficiency declines and the commons is structured in small groups, the most effective strategy resides in contributing only when a majority of individuals are also contributors. In contrast, when group size becomes large, the most effective behaviour follows a minimal-effort rule: contribute only when it is strictly necessary. Both plastic strategies are observed in natural scenarios across scales that present them as relevant social motifs for the sustainable management of public goods.

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

2015 ◽  
Vol 282 (1798) ◽  
pp. 20141994 ◽  
Author(s):  
Miguel dos Santos
Keyword(s):  
Public Goods ◽  
Public Good ◽  
Additional Condition ◽  
Social Dilemmas ◽  
Second Order ◽  
The Public ◽  
Common Pool ◽  
Public Goods Games ◽  
The Commons ◽  
Social Trap

Cooperation in joint enterprises can easily break down when self-interests are in conflict with collective benefits, causing a tragedy of the commons. In such social dilemmas, the possibility for contributors to invest in a common pool-rewards fund, which will be shared exclusively among contributors, can be powerful for averting the tragedy, as long as the second-order dilemma (i.e. withdrawing contribution to reward funds) can be overcome (e.g. with second-order sanctions). However, the present paper reveals the vulnerability of such pool-rewarding mechanisms to the presence of reward funds raised by defectors and shared among them (i.e. anti-social rewarding), as it causes a cooperation breakdown, even when second-order sanctions are possible. I demonstrate that escaping this social trap requires the additional condition that coalitions of defectors fare poorly compared with pro-socials, with either (i) better rewarding abilities for the latter or (ii) reward funds that are contingent upon the public good produced beforehand, allowing groups of contributors to invest more in reward funds than groups of defectors. These results suggest that the establishment of cooperation through a collective positive incentive mechanism is highly vulnerable to anti-social rewarding and requires additional countermeasures to act in combination with second-order sanctions.

scholarly journals Self-reliance crowds out group cooperation and increases wealth inequality

2020 ◽  
Vol 11 (1) ◽  
Author(s):  
Jörg Gross ◽  
Sonja Veistola ◽  
Carsten K. W. De Dreu ◽  
Eric Van Dijk
Keyword(s):  
Public Goods ◽  
Wealth Inequality ◽  
Free Rider ◽  
Public Goods Provision ◽  
Free Rider Problem ◽  
Self Reliance ◽  
Group Cooperation ◽  
The Commons ◽  
Group Members ◽  
Shared Problem

Abstract Humans establish public goods to provide for shared needs like safety or healthcare. Yet, public goods rely on cooperation which can break down because of free-riding incentives. Previous research extensively investigated how groups solve this free-rider problem but ignored another challenge to public goods provision. Namely, some individuals do not need public goods to solve the problems they share with others. We investigate how such self-reliance influences cooperation by confronting groups in a laboratory experiment with a safety problem that could be solved either cooperatively or individually. We show that self-reliance leads to a decline in cooperation. Moreover, asymmetries in self-reliance undermine social welfare and increase wealth inequality between group members. Less dependent group members often choose to solve the shared problem individually, while more dependent members frequently fail to solve the problem, leaving them increasingly poor. While self-reliance circumvents the free-rider problem, it complicates the governing of the commons.

scholarly journals Neighborhood size-effects in nonlinear public goods games

2018 ◽  
Author(s):  
Gregory J. Kimmel ◽  
Philip Gerlee ◽  
Joel S. Brown ◽  
Philipp M. Altrock
Keyword(s):  
Public Goods ◽  
Public Good ◽  
Size Effects ◽  
Evolutionary Dynamics ◽  
Logistic Growth ◽  
Neighborhood Size ◽  
Frequency Dependent ◽  
Frequency Dependent Selection ◽  
The Public ◽  
Public Goods Games

Ecological and evolutionary dynamics can be strongly affected by population assortment and frequency-dependent selection. In growing populations, a particular challenge is to disentangle global ecological effects from local frequency-dependent effects. Here we implement a logistic growth and death model on the global scale, coupled to frequency-dependent growth rates influenced by a public goods game between cooperators and defectors. For each individual, the public good is only effective within a neighborhood of other individuals, and the public good-growth rate relationship can be nonlinear. At low numbers of cooperators, increases of public good accumulate synergistically; at high numbers, increases in public good only provide diminishing returns-the inflection point of this pattern is given by the strength of frequency-dependent selection in relation to the background fitness effect. We observed complex critical behavior in the evolutionary dynamics’ equilibria, determined by the relative magnitude of frequency-dependent to constant (background) growth benefits. We predict neighborhood-size-driven state changes, hysteresis between polymorphic and monomorphic equilibria, and observed that type-dependent differences in neighborhood sizes can destabilize monomorphic cooperative states but increase coexistence of cooperators and defectors. Stochastic neighborhood size fluctuations also led to coexistence and could stabilize the purely cooperative equilibrium. Our results quantify the role of assortment through neighborhood-size effects and nonlinearity of the gains function in eco-evolutionary dynamics, which is relevant for a variety of microbial and cellular public goods games.

scholarly journals Evolution in group-structured populations can resolve the tragedy of the commons

2006 ◽  
Vol 273 (1593) ◽  
pp. 1477-1481 ◽  
Author(s):  
Timothy Killingback ◽  
Jonas Bieri ◽  
Thomas Flatt
Keyword(s):  
Public Goods ◽  
Cognitive Abilities ◽  
Social Dilemma ◽  
Tragedy Of The Commons ◽  
Structured Populations ◽  
Indirect Reciprocity ◽  
The Public ◽  
The Commons ◽  
Animal Societies ◽  
Trait Group

Public goods are the key features of all human societies and are also important in many animal societies. Collaborative hunting and collective defence are but two examples of public goods that have played a crucial role in the development of human societies and still play an important role in many animal societies. Public goods allow societies composed largely of cooperators to outperform societies composed mainly of non-cooperators. However, public goods also provide an incentive for individuals to be selfish by benefiting from the public good without contributing to it. This is the essential paradox of cooperation—known variously as the Tragedy of the Commons, Multi-person Prisoner's Dilemma or Social Dilemma. Here, we show that a new model for evolution in group-structured populations provides a simple and effective mechanism for the emergence and maintenance of cooperation in such a social dilemma. This model does not depend on kin selection, direct or indirect reciprocity, punishment, optional participation or trait-group selection. Since this mechanism depends only on population dynamics and requires no cognitive abilities on the part of the agents concerned, it potentially applies to organisms at all levels of complexity.

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