---
_id: '1922'
abstract:
- lang: eng
  text: We construct two-player two-strategy game-theoretic models of by-product mutualism,
    where our focus lies on the way in which the probability of cooperation among
    players is affected by the degree of adversity facing the players. In our first
    model, cooperation consists of the production of a public good, and adversity
    is linked to the degree of complementarity of the players׳ efforts in producing
    the public good. In our second model, cooperation consists of the defense of a
    public, and/or a private good with by-product benefits, and adversity is measured
    by the number of random attacks (e.g., by a predator) facing the players. In both
    of these models, our analysis confirms the existence of the so-called boomerang
    effect, which states that in a harsh environment, the individual player has few
    incentives to unilaterally defect in a situation of joint cooperation. Focusing
    on such an effect in isolation leads to the "common-enemy" hypothesis that a larger
    degree of adversity increases the probability of cooperation. Yet, we also find
    that a sucker effect may simultaneously exist, which says that in a harsh environment,
    the individual player has few incentives to unilaterally cooperate in a situation
    of joint defection. Looked at in isolation, the sucker effect leads to the competing
    hypothesis that a larger degree of adversity decreases the probability of cooperation.
    Our analysis predicts circumstances in which the "common enemy" hypothesis prevails,
    and circumstances in which the competing hypothesis prevails.
author:
- first_name: Kris
  full_name: De Jaegher, Kris
  last_name: De Jaegher
- first_name: Britta
  full_name: Hoyer, Britta
  id: '42447'
  last_name: Hoyer
citation:
  ama: De Jaegher K, Hoyer B. By-product mutualism and the ambiguous effects of harsher
    environments – A game-theoretic model. <i>Journal of Theoretical Biology</i>.
    2016;393:82-97. doi:<a href="https://doi.org/10.1016/j.jtbi.2015.12.034">10.1016/j.jtbi.2015.12.034</a>
  apa: De Jaegher, K., &#38; Hoyer, B. (2016). By-product mutualism and the ambiguous
    effects of harsher environments – A game-theoretic model. <i>Journal of Theoretical
    Biology</i>, <i>393</i>, 82–97. <a href="https://doi.org/10.1016/j.jtbi.2015.12.034">https://doi.org/10.1016/j.jtbi.2015.12.034</a>
  bibtex: '@article{De Jaegher_Hoyer_2016, title={By-product mutualism and the ambiguous
    effects of harsher environments – A game-theoretic model}, volume={393}, DOI={<a
    href="https://doi.org/10.1016/j.jtbi.2015.12.034">10.1016/j.jtbi.2015.12.034</a>},
    journal={Journal of Theoretical Biology}, publisher={Elsevier BV}, author={De
    Jaegher, Kris and Hoyer, Britta}, year={2016}, pages={82–97} }'
  chicago: 'De Jaegher, Kris, and Britta Hoyer. “By-Product Mutualism and the Ambiguous
    Effects of Harsher Environments – A Game-Theoretic Model.” <i>Journal of Theoretical
    Biology</i> 393 (2016): 82–97. <a href="https://doi.org/10.1016/j.jtbi.2015.12.034">https://doi.org/10.1016/j.jtbi.2015.12.034</a>.'
  ieee: K. De Jaegher and B. Hoyer, “By-product mutualism and the ambiguous effects
    of harsher environments – A game-theoretic model,” <i>Journal of Theoretical Biology</i>,
    vol. 393, pp. 82–97, 2016.
  mla: De Jaegher, Kris, and Britta Hoyer. “By-Product Mutualism and the Ambiguous
    Effects of Harsher Environments – A Game-Theoretic Model.” <i>Journal of Theoretical
    Biology</i>, vol. 393, Elsevier BV, 2016, pp. 82–97, doi:<a href="https://doi.org/10.1016/j.jtbi.2015.12.034">10.1016/j.jtbi.2015.12.034</a>.
  short: K. De Jaegher, B. Hoyer, Journal of Theoretical Biology 393 (2016) 82–97.
date_created: 2018-03-28T11:39:28Z
date_updated: 2022-01-06T06:54:00Z
department:
- _id: '280'
- _id: '475'
doi: 10.1016/j.jtbi.2015.12.034
intvolume: '       393'
page: 82-97
publication: Journal of Theoretical Biology
publication_identifier:
  issn:
  - 0022-5193
publication_status: published
publisher: Elsevier BV
status: public
title: By-product mutualism and the ambiguous effects of harsher environments – A
  game-theoretic model
type: journal_article
user_id: '42447'
volume: 393
year: '2016'
...