@article{65182, abstract = {{The aggregation of rating metrics in reputation systems is crucial for mitigating information overload by condensing customer rating distributions into singular valence scores. While platforms typically employ technical aggregation functions, such as the arithmetic mean to capture product quality, it remains unclear whether these functions align with customers' innate aggregation patterns. To address this knowledge gap, we designed a controlled economic decision experiment to elicit customers' aggregation principles by analyzing their product ranking decisions and contrasting these with various reference functions. Our findings indicate that, on average, customers aggregate rating information in accordance with the arithmetic mean. However, a granular analysis at the individual level reveals significant heterogeneity in aggregation behavior, with a substantial cluster exhibiting binary patterns that focus equally on negative (1-2 star) and positive (4-5 star) ratings. Additional clusters concentrate on negative feedback, particularly 1-star ratings or 1-2 star ratings collectively. Notably, these inherent aggregation patterns exhibit stability across variations in numerical information presentation and are not significantly influenced by individual characteristics, such as online shopping experience, risk attitudes, or demographics. These findings suggest that while the arithmetic mean captures average consumer behavior, platforms could benefit from offering customizable aggregation options to better cater to diverse user preferences for processing rating distributions. By doing so, platforms can enhance the effectiveness of their reputation systems and improve the overall quality of decision-making for consumers.}}, author = {{van Straaten, Dirk and Mir Djawadi, Behnud and Melnikov, Vitalik and Hüllermeier, Eyke and Fahr, René}}, journal = {{SSRN Electronic Journal}}, publisher = {{Elsevier BV}}, title = {{{Aggregation Processes in Customer Rating Systems - Insights from an Economic Decision Experiment}}}, doi = {{http://dx.doi.org/10.2139/ssrn.6201258}}, year = {{2026}}, } @inbook{48387, author = {{Lebedeva, Anastasia and Protte, Marius and van Straaten, Dirk and Fahr, René}}, booktitle = {{Advances in Information and Communication}}, location = {{Berlin}}, pages = {{178–204}}, publisher = {{Springer, Cham}}, title = {{{Involvement of domain experts in the AI training does not affect adherence – An AutoML study}}}, doi = {{https://doi.org/10.1007/978-3-031-53960-2_13}}, volume = {{919}}, year = {{2024}}, } @inbook{45880, author = {{Elrich, Alina and Kaimann, Daniel and Fahr, René and Kundisch, Dennis and Mir Djawadi, Behnud and Müller, Michelle and Poniatowski, Martin and Schäfers, Sabrina and Frick, Bernd}}, booktitle = {{On-The-Fly Computing -- Individualized IT-services in dynamic markets}}, editor = {{Haake, Claus-Jochen and Meyer auf der Heide, Friedhelm and Platzner, Marco and Wachsmuth, Henning and Wehrheim, Heike}}, pages = {{45--64}}, publisher = {{Heinz Nixdorf Institut, Universität Paderborn}}, title = {{{Empirical Analysis in Markets for OTF Services}}}, doi = {{10.5281/zenodo.8068430}}, volume = {{412}}, year = {{2023}}, } @inproceedings{46500, abstract = {{The security of Industrial Control Systems is relevant both for reliable production system operations and for high-quality throughput in terms of manufactured products. Security measures are designed, operated and maintained by different roles along product and production system lifecycles. Defense-in-Depth as a paradigm builds upon the assumption that breaches are unavoidable. The paper at hand provides an analysis of roles, corresponding Human Factors and their relevance for data theft and sabotage attacks. The resulting taxonomy is reflected by an example related to Additive Manufacturing. The results assist in both designing and redesigning Industrial Control System as part of an entire production system so that Defense-in-Depth with regard to Human Factors is built in by design.}}, author = {{Pottebaum, Jens and Rossel, Jost and Somorovsky, Juraj and Acar, Yasemin and Fahr, René and Arias Cabarcos, Patricia and Bodden, Eric and Gräßler, Iris}}, booktitle = {{2023 IEEE European Symposium on Security and Privacy Workshops (EuroS&PW)}}, keywords = {{Defense-in-Depth, Human Factors, Production Engineering, Product Design, Systems Engineering}}, location = {{Delft, Netherlands}}, pages = {{379--385}}, publisher = {{IEEE}}, title = {{{Re-Envisioning Industrial Control Systems Security by Considering Human Factors as a Core Element of Defense-in-Depth}}}, doi = {{10.1109/eurospw59978.2023.00048}}, year = {{2023}}, } @techreport{45616, abstract = {{Aggregation metrics in reputation systems are important for overcoming information overload. When using these metrics, technical aggregation functions such as the arithmetic mean are implemented to measure the valence of product ratings. However, it is unclear whether the implemented aggregation functions match the inherent aggregation patterns of customers. In our experiment, we elicit customers' aggregation heuristics and contrast these with reference functions. Our findings indicate that, overall, the arithmetic mean performs best in comparison with other aggregation functions. However, our analysis on an individual level reveals heterogeneous aggregation patterns. Major clusters exhibit a binary bias (i.e., an over-weighting of moderate ratings and under-weighting of extreme ratings) in combination with the arithmetic mean. Minor clusters focus on 1-star ratings or negative (i.e., 1-star and 2-star) ratings. Thereby, inherent aggregation patterns are neither affected by variation of provided information nor by individual characteristics such as experience, risk attitudes, or demographics.}}, author = {{van Straaten, Dirk and Melnikov, Vitalik and Hüllermeier, Eyke and Mir Djawadi, Behnud and Fahr, René}}, title = {{{Accounting for Heuristics in Reputation Systems: An Interdisciplinary Approach on Aggregation Processes}}}, volume = {{72}}, year = {{2021}}, } @techreport{45618, author = {{van Straaten, Dirk and Fahr, René}}, title = {{{Fighting Fire with Fire - Overcoming Ambiguity Aversion by Introducing more Ambiguity}}}, volume = {{73}}, year = {{2021}}, } @article{21369, abstract = {{Successful design of human-in-the-loop control sys- tems requires appropriate models for human decision makers. Whilst most paradigms adopted in the control systems literature hide the (limited) decision capability of humans, in behavioral economics individual decision making and optimization processes are well-known to be affected by perceptual and behavioral biases. Our goal is to enrich control engineering with some insights from behavioral economics research through exposing such biases in control-relevant settings. This paper addresses the following two key questions: 1) How do behavioral biases affect decision making? 2) What is the role played by feedback in human-in-the-loop control systems? Our experimental framework shows how individuals behave when faced with the task of piloting an UAV under risk and uncertainty, paralleling a real-world decision-making scenario. Our findings support the notion of humans in Cyberphysical Systems underlying behavioral biases regardless of – or even because of – receiving immediate outcome feedback. We observe substantial shares of drone controllers to act inefficiently through either flying excessively (overconfident) or overly conservatively (underconfident). Furthermore, we observe human-controllers to self-servingly misinterpret random sequences through being subject to a “hot hand fallacy”. We advise control engineers to mind the human component in order not to compromise technological accomplishments through human issues.}}, author = {{Protte, Marius and Fahr, René and Quevedo, Daniel E.}}, journal = {{IEEE Control Systems Magazine}}, number = {{6}}, pages = {{57 -- 76}}, publisher = {{IEEE}}, title = {{{Behavioral Economics for Human-in-the-loop Control Systems Design: Overconfidence and the hot hand fallacy}}}, doi = {{10.1109/MCS.2020.3019723}}, volume = {{40}}, year = {{2020}}, } @article{5330, abstract = {{In Internet transactions, customers and service providers often interact once and anonymously. To prevent deceptive behavior a reputation system is particularly important to reduce information asymmetries about the quality of the offered product or service. In this study we examine the effectiveness of a reputation system to reduce information asymmetries when customers may make mistakes in judging the provided service quality. In our model, a service provider makes strategic quality choices and short-lived customers are asked to evaluate the observed quality by providing ratings to a reputation system. The customer is not able to always evaluate the service quality correctly and possibly submits an erroneous rating according to a predefined probability. Considering reputation profiles of the last three sales, within the theoretical model we derive that the service provider’s dichotomous quality decisions are independent of the reputation profile and depend only on the probabilities of receiving positive and negative ratings when providing low or high quality. Thus, a service provider optimally either maintains a good reputation or completely refrains from any reputation building process. However, when mapping our theoretical model to an experimental design we find that a significant share of subjects in the role of the service provider deviates from optimal behavior and chooses actions which are conditional on the current reputation profile. With respect to these individual quality choices we see that subjects use milking strategies which means that they exploit a good reputation. In particular, if the sales price is high, low quality is delivered until the price drops below a certain threshold, and then high quality is chosen until the price increases again.}}, author = {{Mir Djawadi, Behnud and Fahr, Rene and Haake, Claus-Jochen and Recker, Sonja}}, issn = {{1932-6203}}, journal = {{PLoS ONE}}, number = {{11}}, publisher = {{Public Library of Science}}, title = {{{Maintaining vs. Milking Good Reputation when Customer Feedback is Inaccurate}}}, doi = {{10.1371/journal.pone.0207172}}, volume = {{13}}, year = {{2018}}, } @inproceedings{2684, author = {{Klingsieck, K. and Bomm, A. and Djawadi, Behnud and Fahr, Rene and Feldotto, M. and John, Thomas and Kundisch, Dennis and Skopalik, A.}}, booktitle = {{Tagung der Fachgruppen Entwicklungspsychologie und Pädagogische Psychologie (PAEPSY)}}, location = {{Münster}}, title = {{{Study? Now! - Evaluation einer gamifizierten App zur Überwindung von akademischer Prokrastination}}}, year = {{2017}}, } @article{63914, author = {{Mir Djawadi, Behnud and Fahr, René and Turk, Florian}}, issn = {{1556-5068}}, journal = {{SSRN Electronic Journal}}, publisher = {{Elsevier BV}}, title = {{{Tailored Financial Incentives to Fight Medical Non-Persistence in Therapeutic Treatment: A Behavioral Economic Engineering Approach}}}, doi = {{10.2139/ssrn.2713058}}, year = {{2016}}, } @article{228, abstract = {{We investigate the pervasiveness of lying in professional contexts such as insurance fraud, tax evasion and untrue job applications. We argue that lying in professional contexts share three characterizing features: (1) the gain from the dishonest behavior is uncertain, (2) the harm that lying may cause to the other party is only indirect and (3) lies are more indirect lies by action or written statements. Conducted as a field experiment with a heterogenous group of participants during a University ‘‘Open House Day’’, our ‘‘gumball-machineexperiment’’ provides field evidence on how preferences for lying are shaped in situations typically found in professional contexts which we consider to be particularly prone to lying behavior compared to other contexts. As a key innovation, our experimental design allows measuring exact levels of cheating behavior under anonymous conditions. We find clean evidence that cheating is prevalent across all sub groups and that more than 32% of the population cheats for their own gain. However, an analysis of the cheating rates with respect to highest educational degree and professional status reveals that students cheat more than non-students. This finding warrants a careful interpretation of generalizing laboratory findings with student subjects about the prevalence of cheating in the population.}}, author = {{Fahr, Rene and Mir Djawadi, Behnud}}, journal = {{Journal of Economic Psychology}}, pages = {{48--59}}, publisher = {{Elsevier}}, title = {{{“…and they are really lying”: Clean Evidence on the Pervasiveness of Cheating in Professional Contexts from a Field Experiment.}}}, doi = {{10.1016/j.joep.2015.03.002}}, year = {{2015}}, } @inbook{5106, author = {{Fahr, Rene and Foit, Dörte}}, booktitle = {{BWL im Mittelstand - Grundlagen-Besonderheiten-Entwicklungen"}}, editor = {{Becker, W. and Ulrich, P.}}, pages = {{Chapter 4.6.1}}, publisher = {{W. Kohlhammer-Verlag}}, title = {{{Kleine Unternehmen - kleine Verantwortung? Theorie und Praxis unternehmerischer Verantwortung im Mittelstand}}}, year = {{2015}}, } @article{444, abstract = {{BackgroundMedical nonpersistence is a worldwide problem of striking magnitude. Although many fields of studies including epidemiology, sociology, and psychology try to identify determinants for medical nonpersistence, comprehensive research to explain medical nonpersistence from an economics perspective is rather scarce.ObjectivesThe aim of the study was to develop a conceptual framework that augments standard economic choice theory with psychological concepts of behavioral economics to understand how patients’ preferences for discontinuing with therapy arise over the course of the medical treatment. The availability of such a framework allows the targeted design of mechanisms for intervention strategies.MethodsOur conceptual framework models the patient as an active economic agent who evaluates the benefits and costs for continuing with therapy. We argue that a combination of loss aversion and mental accounting operations explains why patients discontinue with therapy at a specific point in time. We designed a randomized laboratory economic experiment with a student subject pool to investigate the behavioral predictions.ResultsSubjects continue with therapy as long as experienced utility losses have to be compensated. As soon as previous losses are evened out, subjects perceive the marginal benefit of persistence lower than in the beginning of the treatment. Consequently, subjects start to discontinue with therapy.ConclusionsOur results highlight that concepts of behavioral economics capture the dynamic structure of medical nonpersistence better than does standard economic choice theory. We recommend that behavioral economics should be a mandatory part of the development of possible intervention strategies aimed at improving patients’ compliance and persistence behavior.}}, author = {{Mir Djawadi, Behnud and Fahr, Rene and Turk, Florian}}, journal = {{Value in Health}}, number = {{8}}, pages = {{814--822}}, publisher = {{Elsevier}}, title = {{{Conceptual Model and Economic Experiments to Explain Nonpersistence and Enable Mechanism Designs Fosterin Behavioral Change}}}, doi = {{10.1016/j.jval.2014.08.2669}}, year = {{2014}}, } @article{4872, author = {{Djawadi, Behnud Mir and Fahr, Rene and Turk, Florian}}, journal = {{Value in Health}}, number = {{8}}, pages = {{814--822}}, title = {{{"Conceptual Model and Economic Experiments to Explain Nonpersistence and Enable Mechanism Designs Fosterin Behavioral Change"}}}, volume = {{17 }}, year = {{2014}}, } @techreport{4922, author = {{Janssen, Elmar and Fahr, Rene}}, title = {{{The Wage Effects of Social Norms-Evidence of Deviations from Peers' Body Mass in Europe}}}, year = {{2014}}, } @misc{5142, author = {{Fahr, Rene}}, booktitle = {{Theologie und Glaube}}, pages = {{260--269}}, title = {{{Vom Wollen und Können ethischen Entscheidens}}}, volume = {{104}}, year = {{2014}}, } @book{5147, author = {{Fahr, Rene}}, pages = {{137--166}}, publisher = {{Klaus von Stoch}}, title = {{{Verantwortungsvolles Handeln in Unternehmen. Die Rolle von kognitiven Verzerrungen und Selbsttäuschung bei ethischen Entscheidungen}}}, year = {{2014}}, } @techreport{5036, author = {{Fahr, Rene and Janssen, Elmar A. and Sureth-Sloane, Caren}}, title = {{{Can Tax Rate Changes Accelerate Investment Under Entry and Exit Flexibility? - Insights from an Economic Experiment}}}, volume = {{166}}, year = {{2014}}, } @article{4880, author = {{St{\, Susi and Fahr, Rene}}, journal = {{Applied Economics}}, number = {{19}}, pages = {{2863----2875}}, title = {{{Individual determinants of work attendance: Evidence on the role of personality}}}, year = {{2013}}, } @book{4911, author = {{Zimmermann, Klaus F and Bauer, Thomas K and Bonin, Holger and Fahr, Rene and Hinte, Holger}}, title = {{{Arbeitskräftebedarf bei hoher Arbeitslosigkeit: ein ökonomisches Zuwanderungskonzept für Deutschland}}}, year = {{2013}}, }