Humans have difficulties grasping the notion of exponential growth and often underestimate the accumulated final value, a phenomenon called exponential growth bias (EGB). During the COVID-19 pandemic, this tendency led to the inaccurate judgment of the virus spread, ultimately making safety measures seem less important. In prospect theory, loss aversion refers to the tendency of perceiving loss as more severe than a gain of the same magnitude is perceived as good. The question addressed was whether loss aversion through the valence of framing influences the judgments of exponential changes within the context of COVID-19. Furthermore, the association between EGB and the individual characteristic Need for Cognition (NFC) was investigated. Participants (n=129) were randomized into one of the two framing conditions (Recovery or Infection) and were presented with six EGB problems with different change rates and the six-item version of the Need for Cognition Scale. The results confirmed the existence of EGB at all growth rates (+5%, +15%, +25%), while the effect of EGB was mixed for exponential decline. The framing did not show a considerable effect on the accuracy of judgments. Simple linear regression analyses indicated that NFC moderates the effect of EGB at higher growth rates (i.e., at +15% and +25%). Overall, the results were more consistent and clearer for exponential growth than for exponential decline. The underestimation of exponential growth in the context of COVID-19 is quite alarming as it entails the risk of insufficient behavioral changes, which can lead to serious consequences for both the individual and society.

Background: As more individuals continuously become more conscious of the external influences of their decisions, integrating social and ethical criteria and perceived non-monetary value in their investment decisions, the interest in socially responsible investments (SRI) has escalated in the past decade. Reflecting this shift, the Swedish Pension Agency continuously increases the requirements and sustainability demands for the funds available in the premium pension selection. To investigate the underlying variables affecting the decision to invest socially responsibly, the authors of this thesis studied Swedish pension beneficiaries’ demographics, attitudes and beliefs.  Purpose: The purpose of this thesis is to examine the socio-demographic and psychological determinants of pension beneficiaries' and the influence of these variables on the willingness to pay for socially responsible investments. The study will additionally explore the tendency to underestimate exponential growth in one’s pension savings.  Method: The study is conducted by collecting primary data in the form of quantitative research through an online questionnaire. Based on previous research, six hypotheses are developed. This in order to investigate the relationship between willingness to pay for socially responsible investments and several socio-demographic and psychographic variables. Additionally, to examine Swedish pension beneficiaries’ tendency to underestimate exponential growth. The data collected is analysed through a multiple linear regression model and other descriptive statistics to examine if the hypotheses are rejected or not.  Conclusion: The majority of the subjects in the study are willing to pay for SRI. Gender significantly impacts the willingness to pay for SRI, as men demonstrate a lower willingness to pay than women. Furthermore, altruistic values, concern for one’s pension savings, concern for ESG-related issues (environmental, social and governance) and perceived consumer effectiveness proves to have a significant impact on the willingness to pay for SRI. Further, the sample demonstrated a definite tendency to underestimate exponential growth.

Der verhaltensökonomischen Literatur entsprechend behandeln die drei Kapitel dieser Dissertation unterschiedliche Aspekte des menschlichen Verhaltens, welches als "nicht-rational" zu bezeichnen ist. Jedes dieser Kapitel leistet einen Beitrag zum aktuellen Stand der Forschung auf dem Gebiet der Verhaltensökonomik mit Hilfe von entweder experimentellen, empirischen oder methodischen Ansätzen. Das erste Kapitel schlägt ein einfaches verhaltensökonomisches Modell vor und unterzieht dieses einer Reihe von experimentellen Tests. Das Modell erweitert die Literatur zur Fehlwahrnehmung von multiplikativen Wachstumsprozessen und hilft somit typische Fehlinvestitionen in der langen Frist zu erklären. Im Rahmen des zweiten Kapitels werden Daten einer Online-Kreditbörse genutzt, um empirisch zu untersuchen, ob sich private Investoren entsprechend den Vorhersagen der standardmäßigen ökonomischen Fachliteratur verhalten und einzig die erwartete Rendite berücksichtigen oder ob sie von anderen nicht-finanztechnischen Attributen eines Schuldners beeinflusst werden. Der Schwerpunkt der Analyse liegt dabei auf Geschlechterdiskriminierung im Rahmen dessen unterschiedliche Diskriminierungskonzepte getestet werden. Das dritte Kapitel wählt einen methodischen Ansatz und schlägt ein innovatives Experiment-Design vor, welches den empirisch gut dokumentierten Schwierigkeiten bzgl. der Angabe von subjektiven Wahrscheinlichkeiten von Teilnehmern an Umfragen und Laborexperimenten Rechnung trägt. Ein Binary-Choice-Ansatz eingebettet in ein adaptives Experiment-Design minimiert den Aufwand für die Befragten und ermöglich somit eine praktikable und effiziente Elizitierung der subjektiven Meinungen. / In the line with the literature on behavioral economics, the three chapters of this dissertation shed light on different aspects of human behavior that are at odds with rationality. Each chapter contributes to the existing behavioral economic research using either experimental, empirical, or methodological tools. First, by proposing and experimentally testing a simple behavioral model that extends the literature on the misperception of multiplicative growth processes, Chapter 1 aims to explain common money mistakes that people often make with long-term investments such as retirement savings plans. Second, in Chapter 2, real-life investment data of an online-lending platform are used to empirically investigate if private investors behave as the standard economic literature would predict and solely consider an investment’s expected return or if they also care about other non-financial attributes of a debtor. The focus of the analysis is on gender discrimination, thereby defining and econometrically testing different concepts of how investors discriminate between male and female borrowers. Third, Chapter 3 takes a methodological path and proposes a novel experimental design that accounts for the empirically well-documented difficulties that survey respondents typically have when asked to state subjective probabilities. A binary choice approach embedded in an adaptive experimental design helps to minimize effort of the respondents, thus allowing for a more practical belief elicitation in both the lab and the field.

People use shortcuts to make decisions to efficiently deal with a large volume of information. Linear thinking is one shortcut and it contributes to exponential growth bias which means underestimation of exponential growth values. This study examined differences in exponential growth bias in the context of the stock market and COVID-19 cases. Moreover, this research analyzed correlation between exponential growth bias and worry for health and for the economy in the contexts of COVID-19 and stock market. A total of 120 participants completed an online survey in which they were randomly assigned to the COVID-19 or stock market group. A 2 x 3 repeated measures ANOVA showed no significant differences depending on the group. Moreover, ANOVA showed that bias increased in line with the increase in the percentages analyzed for both groups. Exploratory Pearson analysis showed that there was a significant negative correlation between worry for the economy and exponential growth bias of 15% and 40% growth scenarios in COVID-19 group. There were no significant correlations between worry for the economy or health in the stock market group. The conclusion is that people use shortcuts which leads them to biased decision- making. For example, when calculating exponential values, people think linearly and it leads them to exponential growth bias, what in practice results in estimating values lower than they are. Interventions, as education with aim to reduce exponential growth bias are proposed for the future research.