Ambiguity aversion as a reason to choose tournaments

We test the implications of ambiguity aversion in a principal-agent problem with multiple agents. When output distributions are uncertain, models of ambiguity aversion suggest that tournaments may become more attractive than independent wage contracts, in contrast to the case where output distributions are known. We do so by presenting agents with a choice between tournaments and independent contracts, which are designed in a way that under uncertainty about output distribution (that is, under ambiguity), ambiguity averse agents should typically prefer tournaments, while ambiguity neutral agents prefer independent contracts, independent of their degree of risk aversion. This is the case, because the tournament removes all ambiguity about the equilibrium wages. We compare the share of participants who choose the tournament under ambiguity with the share of participants choosing the tournament in a control treatment, where output distributions are know. As the theory predicts, we find indeed that under ambiguity the share of agents who choose the tournaments is higher than in the case of known output distributions.Ambiguity aversion, tournaments, Ellsberg urn, contract design

Numerical Investigation of Signal Launch Imperfections for Edge Mount RF Connectors

In this paper, common practice RF design guidelines for SMA edge mount connectors are investigated in terms of numerical simulations and VNA measurements. These guidelines are used in a variety of applications for coaxial-to-planar interfaces but often do not provide information regarding the physical origins of increased insertion and transmission losses. The presented results in this work focus on different RF PCB design features and their impact on electromagnetic field distributions in the launching zone. The presented investigations should raise awareness on the issue of electromagnetic field resonances occurring in the RF frequency range and assist PCB design engineers to identify potential issues occurring at an coaxial-to-planar interface. The investigated PCB features facilitate a high performance RF PCB design up to a frequency of 26 GHz

Reacting to ambiguous messages: An experimental analysis

Ambiguous language is ubiquitous and often deliberate. Recent theoretical work (See Bose and Renou (2014), Kellner and Le Quement (2018), Beauchene et al. (2019)) has shown how language ambiguation can improve outcomes by mitigating conflict of interest. Our experiment finds a significant effect of language ambiguation on subjects who are proficient at Bayesian updating. For ambiguity averse subjects within this population, a significant part of this effect operates via the channel of subjects' desire to reduce ambiguity. For both ambiguity averse and neutral subjects within this population, an additional behavioral channel is also present

Giving and Probability

When and how should a fundraiser ask for a donation from an individual facing an uncertain bonus income? A standard model of expected utility over outcomes predicts that the individual’s before choice – her ex-ante commitment conditional on her income – will be the same as her choice after the income has been revealed. Deciding “if you win, how much will you donate?” involves a commitment (i) over a donation for a state of the world that may not be realized and (ii) over uncertain income. Models involving reference-dependent utility, tangibility, and self-signaling predict more giving before, while theories of affect predict more giving after. In our online field experiment at a UK university, as well as in our laboratory experiments in Germany, charitable giving was significantly larger in the Before treatment than in the After treatment for male subjects, with a significant gender differential. Lab treatments isolated distinct mechanisms: for men, donations were higher in all treatments where the donation’s collection was uncertain, whether or not the income was known. This supports a (self)-signaling explanation: commitments realized with a lower probability must involve larger amounts to have the same signaling power. Our results are directly relevant to fundraising and volunteer-recruitment strategies,and offer further evidence that we need to exercise caution in applying expected-utility theory in the presence of social preferences

The effect of ambiguity aversion on reward scheme choice

We test the implications of ambiguity aversion in a principal-agent problem with multiple agents. Models of ambiguity aversion suggest that, under ambiguity, comparative compensation schemes may become more attractive than independent wage contracts. We test this by presenting agents with a choice between comparative reward schemes and independent contracts, which are designed such that under uncertainty about output distributions (that is, under ambiguity), ambiguity averse agents should typically prefer comparative reward schemes, independent of their degree of risk aversion. We indeed find that the share of agents who choose the comparative scheme is higher under ambiguity.</p

Outline of Synthesis of Cognitive and Socio-cultural Foundations of Scientific Knowledge Evolution in Research Programs of Western Philosophy of Science

The article analyses the development of cognitive sociology of science, in the object field of which connection of cognitive and social structures of science is traced. The role of context in scientific knowledge formation is defined. It is stated that the basis for development of research program of cognitive sociology of science appeared to be reconsideration of the standard concept of science as a complex of gnoseological, epistemological and methodological interpretations of nature and morphology of the produced scientific knowledge, methods for its explanation and scientificity ideals. The difference between "strong" and «weak» varieties of scientific knowledge evolution, developed in western philosophy of science, is considered. "Social studies of science" are reviewed as a form of social constructivism and relativism, exhibiting their specific nature in macro-analytical and micro- analytical strategies of scientific knowledge evolution analysis. The thesis that multidimensionality of science cannot be adequately interpreted focusing only on conceptual history of science is proved

Entwicklung eines nichtlinearen Finite Elemente Simulationsmodells zur Nachbildung des Crash-Verhaltens von gewebeverstärkten CFK/Epoxid-Laminaten

Zusammenfassung in englischer SpracheIn der heutigen Industrie nimmt der Einsatz von faserverstärkten Kunststoffen (FVK) aufgrund ihrer hervorragenden Eigenschaften mehr und mehr zu. Sie ersetzen dabei klassische Konstruktionswerkstoffe und werden für die Realisierung von Strukturbauteilen verwendet. Des Weiteren werden FVK auch zunehmend für den Einsatz in sicherheitsrelevanten Bauteilen wie z.B. Crash-Absorber bewertet. FVK weisen ein Versagensverhalten auf, welches bei der Zerstörung des Werkstoffes mit einem hohen, auf die Dichte bezogenem, Energieaufnahmevermögen einhergeht. Komponententests sind aufwendig und teuer, weshalb die Entwicklung von Simulationsmodellen, welche das Crash-Verhalten hinreichend genau vorhersagen, unerlässlich ist. In dieser Arbeit werden die ersten Schritte der Erstellung eines Simulationsmodells für eine Composite Crash-Box eines Formula Student Rennfahrzeuges behandelt, wobei die finale Berechnung der Crash-Box nicht Teil dieser Arbeit ist. Das Ziel dieser Arbeit besteht viel mehr darin, ein nichtlineares Finite Elemente Modell zu entwickeln, welches in der Lage ist, das Crash-Verhalten von CFK/Epoxid-Laminaten mit einfacher Geometrie nachzubilden. Um dies zu erreichen, erfolgt die Modellgenerierung nach dem "Building Block Approch". Dieser stellt eine Vorgehensweise dar, welche sich zur Bewältigung einer solchen komplexen Aufgabenstellung eignet, da die benötigten Simulationsparameter Schritt für Schritt ermittelt werden. Bei der Simulation von Crash-Vorgängen handelt es sich um eine kurzzeitdynamische Problemstellung, weshalb in dieser Arbeit die explizite finite Elemente Methode zum Einsatz kommt. Des Weiteren ist es von großer Bedeutung, alle relevanten Versagensmechanismen (Faser-/Matrixbruch, Delamination von Einzelschichten) zu erfassen, welche für die Energiedissipation während des Crash-Vorgangs maßgeblich sind. Dabei wird als Modellierungsansatz ein "Stacked Shell Approach" gewählt, mit dessen Hilfe die intralaminare Einzelschichtschädigung und interlaminare Delamination von CFK/Epoxid-Laminaten nachgebildet werden kann. Für die Berechnung der Einzellagen wird dabei ein kontinuumsmechanisches Schädigungsmodell verwendet. Die Schädigung der interlaminaren Interfaceschichten wird über ein Kohäsivzonenmodell und Separationsgesetze beschrieben. Die Entwicklung des numerischen Modells erfolgt schrittweise durch die Nachbildung von Materialtests, wie sie in der Praxis durchgeführt werden. Die Kalibrierung des Materialmodells der Einzellagen erfolgt dabei anhand von Simulationsmodellen, welche Zug-, Druck- und Schubversuchen nachbilden. Die Kalibrierung der Kohäsiv-Elemente erfolgt anhand von Simulationen von DCB- und ENF Modellen, wobei näher auf das Themengebiet der virtuellen Streckung der kohäsiven Zone eingegangen wird. Die benötigten Simulationsparameter werden dabei anhand von Gleichungen angenähert. Die Simulationsergebnisse werden in weiterer Folge mit analytisch berechneten Kurvenverläufen verglichen. Ist die Kalibrierung der Materialmodelle soweit abgeschlossen, wird deren Eignung anhand von Crash-Simulationen von Platten mit rechteckförmiger Geometrie und keilförmigen Triggermechanismus durchgeführt. Die Ergebnisse werden dabei mit Daten und Erkenntnissen, welche aus der Literatur entnommen wurden, verglichen und bewertet. Dabei wird gezeigt, dass die entwickelten Materialmodelle in der Lage sind, die komplexen Versagensformen von CFK/Epoxid-Laminaten sowie die Kraft-/Verschiebungsverläufe von realen Prüfkörpern nachzubilden.The usage of fiber reinforced plastics (FRP) in today's industry is highly increasing. Reasons for this development are the excellent properties of these group of materials. FRPs replace more and more typical construction materials and are applied in structural parts. In addition to the usage in this field, FRPs are getting in the last years attractive in Crash and Occupant safety applications. FRPs shows a failure behavior which is coupled with a high, related to the density, energy absorption. Component testing is time consuming and expensive, so the development of effective simulation models, which can describe the crash behavior of fiber reinforced crash-elements, is necessary. Target of this work is to generate the first steps of a nonlinear finite element simulation model of a composite crash-box which is used in a formula student race car. At this point, it has to be mentioned, that the final simulation of the crash-box is not part of this thesis. The target consists therein, to create a numerical model which catches accurately the crash behavior of simple plates which consists of fabric CFK/epoxy laminates. To reach this purpose, the development of the model follows the Building Block Approach which is a useful and, related to simulation time, cost-efficient tool to manage this sort of complex problem. Although the parameters which are necessary for the simulation are estimated step by step. Simulation of crash is a problem where dynamic processes appear in a very short timescale so the explicit finite element method is used for simulations. In crash analysis of FRPs, it is very important to catch all relevant failure mechanisms (Fiber-, Matrix-cracking, Delamination of Plys) to reach the necessary accuracy regarding the absorbed energy. By application of an stacked shell approach, the failure mechanisms of the plys and the intra-laminar interfaces can be captured. For the calculation of the single plys, a continuum damage model is chosen. The damage process of the Interface-material between the single plys is considered by a cohesive zone modeling approach and separation laws. The development of the numerical models is done step by step by recreation of material test which are used in practical applications. The calibration of the material models of the single plys is done by simulation models, which recreate tensile, compression and shear tests. The cohesive elements are calibrated by performing Simulations of DCB- and ENF-Tests where in the topic of artificial extension of the cohesive zone is examined. The estimation of the parameters which are needed for the simulation is done by approximation equations. The results which are obtained from simulations are compared with analytical estimated curves. After the calibration processes of the material models are done, the crash behavior of a wedged composite plate is investigated. To check for accuracy, the simulation results will be compared to results and perceptions which were extracted from literature. It is proposed that the developed model has the capability to recreate the results from real component tests like regarding the failure mechanisms and the force/displacement curves.9

The effect of ambiguity aversion on reward scheme choice

We test the implications of ambiguity aversion in a principal-agent problem with multiple agents. Models of ambiguity aversion suggest that, under ambiguity, comparative compensation schemes may become more attractive than independent wage contracts. We test this by presenting agents with a choice between comparative reward schemes and independent contracts, which are designed such that under uncertainty about output distributions (that is, under ambiguity), ambiguity averse agents should typically prefer comparative reward schemes, independent of their degree of risk aversion. We indeed find that the share of agents who choose the comparative scheme is higher under ambiguity.</p

Norms, moods, and free lunch: Longitudinal evidence on payments from a Pay-What-You-Want restaurant

We study the distribution and evolution of payments in a Pay-What-You-Want restaurant. Despite missing price tags and despite the option to pay nothing at all, we observe that the vast majority of guests makes strictly positive payments. Over the two years covered by our data, average payments decline slightly, converging at a positive level. At the same time, the number of daily guests increases steadily, resulting in a considerable increase in total revenues. We discuss one possible interpretation of the long-term trend in payments in terms of social norms. We further show that short-term fluctuations in average payments are partly explained by exogenous weather changes. We provide evidence that – in line with work in psychology – weather-induced changes in mood affect payments