@misc{HeuerOrland2019,
  author    = {Heuer, Leonie and Orland, Andreas},
  title     = {Cooperation in the Prisoner's Dilemma},
  series = {Postprints der Universit{\"a}t Potsdam Wirtschafts- und Sozialwissenschaftliche Reihe},
  journal   = {Postprints der Universit{\"a}t Potsdam Wirtschafts- und Sozialwissenschaftliche Reihe},
  number    = {107},
  issn      = {1867-5808},
  doi       = {10.25932/publishup-43592},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-435929},
  pages     = {9},
  year      = {2019},
  abstract  = {Cooperation is — despite not being predicted by game theory — a widely documented aspect of human behaviour in Prisoner's Dilemma (PD) situations. This article presents a comparison between subjects restricted to playing pure strategies and subjects allowed to play mixed strategies in a one-shot symmetric PD laboratory experiment. Subjects interact with 10 other subjects and take their decisions all at once. Because subjects in the mixed-strategy treatment group are allowed to condition their level of cooperation more precisely on their beliefs about their counterparts' level of cooperation, we predicted the cooperation rate in the mixed-strategy treatment group to be higher than in the pure-strategy control group. The results of our experiment reject our prediction: even after controlling for beliefs about the other subjects' level of cooperation, we find that cooperation in the mixed-strategy group is lower than in the pure-strategy group. We also find, however, that subjects in the mixedstrategy group condition their cooperative behaviour more closely on their beliefs than in the pure-strategy group. In the mixed-strategy group, most subjects choose intermediate levels of cooperation.},
  language  = {en}
}
@article{HeuerOrland2019,
  author    = {Heuer, Leonie and Orland, Andreas},
  title     = {Cooperation in the Prisoner's Dilemma},
  series = {Royal Society Open Science},
  volume    = {6},
  journal   = {Royal Society Open Science},
  publisher = {Royal Soc. Publ.},
  address   = {London},
  issn      = {2054-5703},
  doi       = {10.1098/rsos.182142},
  pages     = {9},
  year      = {2019},
  abstract  = {Cooperation is — despite not being predicted by game theory — a widely documented aspect of human behaviour in Prisoner's Dilemma (PD) situations. This article presents a comparison between subjects restricted to playing pure strategies and subjects allowed to play mixed strategies in a one-shot symmetric PD laboratory experiment. Subjects interact with 10 other subjects and take their decisions all at once. Because subjects in the mixed-strategy treatment group are allowed to condition their level of cooperation more precisely on their beliefs about their counterparts' level of cooperation, we predicted the cooperation rate in the mixed-strategy treatment group to be higher than in the pure-strategy control group. The results of our experiment reject our prediction: even after controlling for beliefs about the other subjects' level of cooperation, we find that cooperation in the mixed-strategy group is lower than in the pure-strategy group. We also find, however, that subjects in the mixedstrategy group condition their cooperative behaviour more closely on their beliefs than in the pure-strategy group. In the mixed-strategy group, most subjects choose intermediate levels of cooperation.},
  language  = {en}
}
@techreport{BruttelFelgendreherGuethetal.2019,
  type      = {Working Paper},
  author    = {Bruttel, Lisa Verena and Felgendreher, Simon and G{\"u}th, Werner and Hertwig, Ralph},
  title     = {Strategic ignorance in repeated prisoners' dilemma experiments and its effects on the dynamics of voluntary cooperation},
  series = {CEPA Discussion Papers},
  journal   = {CEPA Discussion Papers},
  number    = {10},
  issn      = {2628-653X},
  doi       = {10.25932/publishup-43188},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-431881},
  pages     = {30},
  year      = {2019},
  abstract  = {Being ignorant of key aspects of a strategic interaction can represent an advantage rather than a handicap. We study one particular context in which ignorance can be beneficial: iterated strategic interactions in which voluntary cooperation may be sustained into the final round if players voluntarily forego knowledge about the time horizon. We experimentally examine this option to remain ignorant about the time horizon in a finitely repeated two-person prisoners' dilemma game. We confirm that pairs without horizon knowledge avoid the drop in cooperation that otherwise occurs toward the end of the game. However, this effect is superposed by cooperation declining more rapidly in pairs without horizon knowledge during the middle phase of the game, especially if players do not know that the other player also wanted to remain ignorant of the time horizon.},
  language  = {en}
}