@techreport{Andres2024, type = {Working Paper}, author = {Andres, Maximilian}, title = {Equilibrium selection in infinitely repeated games with communication}, series = {CEPA Discussion Papers}, journal = {CEPA Discussion Papers}, number = {75}, issn = {2628-653X}, doi = {10.25932/publishup-63180}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-631800}, pages = {38}, year = {2024}, abstract = {The present paper proposes a novel approach for equilibrium selection in the infinitely repeated prisoner's dilemma where players can communicate before choosing their strategies. This approach yields a critical discount factor that makes different predictions for cooperation than the usually considered sub-game perfect or risk dominance critical discount factors. In laboratory experiments, we find that our factor is useful for predicting cooperation. For payoff changes where the usually considered factors and our factor make different predictions, the observed cooperation is consistent with the predictions based on our factor.}, language = {en} } @techreport{AndresBruttel2024, type = {Working Paper}, author = {Andres, Maximilian and Bruttel, Lisa}, title = {Communicating Cartel Intentions}, series = {CEPA Discussion Papers}, journal = {CEPA Discussion Papers}, number = {77}, issn = {2628-653X}, doi = {10.25932/publishup-63846}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-638469}, pages = {36}, year = {2024}, abstract = {While the economic harm of cartels is caused by their price-increasing effect, sanctioning by courts rather targets at the underlying process of firms reaching a price-fixing agreement. This paper provides experimental evidence on the question whether such sanctioning meets the economic target, i.e., whether evidence of a collusive meeting of the firms and of the content of their communication reliably predicts subsequent prices. We find that already the mere mutual agreement to meet predicts a strong increase in prices. Conversely, express distancing from communication completely nullifies its otherwise price-increasing effect. Using machine learning, we show that communication only increases prices if it is very explicit about how the cartel plans to behave.}, language = {en} } @article{AndresBruttelFriedrichsen2022, author = {Andres, Maximilian and Bruttel, Lisa and Friedrichsen, Jana}, title = {How communication makes the difference between a cartel and tacit collusion}, series = {European economic review}, volume = {152}, journal = {European economic review}, publisher = {Elsevier}, address = {Amsterdam}, issn = {0014-2921}, doi = {10.1016/j.euroecorev.2022.104331}, pages = {1 -- 18}, year = {2022}, abstract = {This paper sheds new light on the role of communication for cartel formation. Using machine learning to evaluate free-form chat communication among firms in a laboratory experiment, we identify typical communication patterns for both explicit cartel formation and indirect attempts to collude tacitly. We document that firms are less likely to communicate explicitly about price fixing and more likely to use indirect messages when sanctioning institutions are present. This effect of sanctions on communication reinforces the direct cartel-deterring effect of sanctions as collusion is more difficult to reach and sustain without an explicit agreement. Indirect messages have no, or even a negative, effect on prices.}, language = {en} } @techreport{AndresBruttelFriedrichsen2020, type = {Working Paper}, author = {Andres, Maximilian and Bruttel, Lisa Verena and Friedrichsen, Jana}, title = {Choosing between explicit cartel formation and tacit collusion - An experiment}, series = {CEPA Discussion Papers}, journal = {CEPA Discussion Papers}, number = {19}, issn = {2628-653X}, doi = {10.25932/publishup-47388}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-473885}, pages = {55}, year = {2020}, abstract = {Numerous studies investigate which sanctioning institutions prevent cartel formation but little is known as to how these sanctions work. We contribute to understanding the inner workings of cartels by studying experimentally the effect of sanctioning institutions on firms' communication. Using machine learning to organize the chat communication into topics, we find that firms are significantly less likely to communicate explicitly about price fixing when sanctioning institutions are present. At the same time, average prices are lower when communication is less explicit. A mediation analysis suggests that sanctions are effective in hindering cartel formation not only because they introduce a risk of being fined but also by reducing the prevalence of explicit price communication.}, language = {en} } @techreport{AndresBruttelFriedrichsen2022, type = {Working Paper}, author = {Andres, Maximilian and Bruttel, Lisa Verena and Friedrichsen, Jana}, title = {How communication makes the difference between a cartel and tacit collusion}, series = {CEPA Discussion Papers}, journal = {CEPA Discussion Papers}, issn = {2628-653X}, doi = {10.25932/publishup-56223}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-562234}, pages = {67}, year = {2022}, abstract = {This paper sheds new light on the role of communication for cartel formation. Using machine learning to evaluate free-form chat communication among firms in a laboratory experiment, we identify typical communication patterns for both explicit cartel formation and indirect attempts to collude tacitly. We document that firms are less likely to communicate explicitly about price fixing and more likely to use indirect messages when sanctioning institutions are present. This effect of sanctions on communication reinforces the direct cartel-deterring effect of sanctions as collusion is more difficult to reach and sustain without an explicit agreement. Indirect messages have no, or even a negative, effect on prices.}, language = {en} } @techreport{BruttelPetrishcheva2024, type = {Working Paper}, author = {Bruttel, Lisa Verena and Petrishcheva, Vasilisa}, title = {Does communication increase the precision of beliefs?}, series = {CEPA Discussion Papers}, journal = {CEPA Discussion Papers}, number = {74}, issn = {2628-653X}, doi = {10.25932/publishup-62936}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-629367}, pages = {1 -- 33}, year = {2024}, abstract = {In this paper, we study one channel through which communication may facilitate cooperative behavior - belief precision. In a prisoner's dilemma experiment, we show that communication not only makes individuals more optimistic that their partner will cooperate but also increases the precision of this belief, thereby reducing strategic uncertainty. To disentangle the shift in mean beliefs from the increase in precision, we elicit beliefs and precision in a two-stage procedure and in three situations: without communication, before communication, and after communication. We find that the precision of beliefs increases during communication.}, language = {en} } @article{BruttelStolley2020, author = {Bruttel, Lisa Verena and Stolley, Florian}, title = {Getting a yes}, series = {Journal of behavioral and experimental economics}, volume = {86}, journal = {Journal of behavioral and experimental economics}, publisher = {Elsevier}, address = {New York}, issn = {2214-8043}, doi = {10.1016/j.socec.2020.101550}, pages = {10}, year = {2020}, abstract = {This paper studies how the request for a favor has to be devised in order to maximize its chance of success. We present results from a mini-dictator game, in which the recipient can send a free-form text message to the dictator before the latter decides. We find that putting effort into the message, writing in a humorous way and mentioning reasons why the money is needed pays off. Additionally, we find differences in the behavior of male and female dictators. Only men react positively to efficiency arguments, while only women react to messages that emphasize the dictators power and responsibility.}, language = {en} } @techreport{BruttelStolleyUtikal2019, type = {Working Paper}, author = {Bruttel, Lisa Verena and Stolley, Florian and Utikal, Verena}, title = {Getting a Yes}, series = {CEPA Discussion Papers}, journal = {CEPA Discussion Papers}, number = {2}, issn = {2628-653X}, doi = {10.25932/publishup-42763}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-427638}, year = {2019}, abstract = {This paper studies how the request for a favor has to be devised in order to maximize its chance of success. We present results from a mini-dictator game, in which the recipient can send a free-form text message to the dictator before the latter decides. We find that putting effort into the message, writing in a humorous way and mentioning reasons why the money is needed pays off. Additionally, we find differences in the behavior of male and female dictators. Only men react positively to efficiency arguments, while only women react to messages that emphasize the dictator's power and responsibility.}, language = {en} } @misc{GellertHaeuslerSuhretal.2018, author = {Gellert, Paul and H{\"a}usler, Andreas and Suhr, Ralf and Gholami, Maryam and Rapp, Michael A. and Kuhlmey, Adelheid and Nordheim, Johanna}, title = {Testing the stress-buffering hypothesis of social support in couples coping with early-stage dementia}, series = {Postprints der Universit{\"a}t Potsdam : Humanwissenschaftliche Reihe}, journal = {Postprints der Universit{\"a}t Potsdam : Humanwissenschaftliche Reihe}, number = {657}, issn = {1866-8364}, doi = {10.25932/publishup-44627}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-446270}, pages = {16}, year = {2018}, abstract = {Purpose To test whether the negative relationship between perceived stress and quality of life (Hypothesis 1) can be buffered by perceived social support in patients with dementia as well as in caregivers individually (Hypothesis 2: actor effects) and across partners (Hypothesis 3: partner effects and actor-partner effects). Method A total of 108 couples (N = 216 individuals) comprised of one individual with early-stage dementia and one caregiving partner were assessed at baseline and one month apart. Moderation effects were investigated by applying linear mixed models and actor-partner interdependence models. Results Although the stress-quality of life association was more pronounced in caregivers (beta = -.63, p<.001) compared to patients (beta= -.31, p<.001), this association was equally moderated by social support in patients (beta = .14, p<.05) and in the caregivers (beta =.13, p<.05). From one partner to his or her counterpart, the partner buffering and actor-partner-buffering effect were not present. Conclusion The stress-buffering effect has been replicated in individuals with dementia and caregivers but not across partners. Interventions to improve quality of life through perceived social support should not only focus on caregivers, but should incorporate both partners.}, language = {en} } @article{HauptWolschkeRabeetal.2017, author = {Haupt, T. and Wolschke, M. and Rabe, Sophie and Scholz, I. and Smurawski, A. and Salzwedel, Annett and Thomas, F. and Reich, H. and V{\"o}ller, Heinz and Liebach, J. and Eichler, Sarah}, title = {ReMove-It - Entwicklung einer telemedizinisch assistierten Bewegungstherapie f{\"u}r die Rehabilitation nach Intervention an der unteren Extremit{\"a}t}, series = {B\&G Bewegungstherapie und Gesundheitssport}, volume = {33}, journal = {B\&G Bewegungstherapie und Gesundheitssport}, number = {5}, publisher = {Thieme}, address = {Stuttgart}, issn = {1613-0863}, doi = {10.1055/s-0043-118139}, pages = {221 -- 226}, year = {2017}, abstract = {Knie- und H{\"u}ftgelenksarthrose z{\"a}hlen zu den zehn h{\"a}ufigsten Einzeldiagnosen in orthop{\"a}dischen Praxen. Die Wirksamkeit einer station{\"a}ren Rehabilitation f{\"u}r Patienten nach Knie- oder H{\"u}ft-Totalendoprothese (TEP) ist in mehreren Studien belegt. Dennoch stellt die mittel- und langfristige Nachhaltigkeit zum Erhalt des Therapieerfolges eine große Herausforderung dar. Das Ziel des Projekts ReMove-It ist es, einen Wirksamkeitsnachweis f{\"u}r eintelemedizinisch assistiertes Interventionstraining f{\"u}r Patienten nach einem operativen Eingriff an den unteren Extremit{\"a}ten zu erbringen. In dem Beitrag wird anhand von Erfahrungsberichten dargestellt, wie das interaktive {\"U}bungsprogramm f{\"u}r Knie- und H{\"u}ft-TEP-Patienten entwickelt und das telemedizinische Assistenzsystem MeineReha® in den Behandlungsalltag von drei Rehakliniken integriert wurde. Ebenso werden der Aufbau und Ablauf der klinischen Studie dargestellt und das System aus Sicht der beteiligten {\"A}rzte, und Therapeuten bewertet.}, language = {de} }