Temporal Discounting in Software Engineering : A Replication Study

Background: Many decisions made in Software Engineering practices are intertemporal choices: trade-offs in time between closer options with potential short-term benefit and future options with potential long-term benefit. However, how software professionals make intertemporal decisions is not well understood. Aim: This paper investigates how shifting time frames influence preferences in software projects in relation to purposefully selected background factors. Method: We investigate temporal discounting by replicating a questionnaire-based observational study. The replication uses a changed-population and -experimenter design to increase the internal and external validity of the original results. Results: The results of this study confirm the occurrence of temporal discounting in samples of both professional and student participants from different countries and demonstrate strong variance in discounting between study participants. We found that professional experience influenced discounting. Participants with broader professional experience exhibited less discounting than those with narrower experience. Conclusions: The results provide strong empirical support for the relevance and importance of temporal discounting in SE and the urgency of targeted interdisciplinary research to explore the underlying mechanisms and their theoretical and practical implications. The results suggest that technical debt management could be improved by increasing the breadth of experience available for critical decisions with long-term impact. In addition, the present study provides a methodological basis for replicating temporal discounting studies in software engineering.Peer reviewe

The coordination value of monetary exchange: Experimental evidence

Under what conditions can cooperation be sustained in a network of strangers? Here we study the role of institutions and uncover a new behavioral foundation for the use of monetary systems. In an experiment, anonymous subjects could cooperate or defect in bilateral random encounters. This sequence of encounters was indefinite; hence multiple equilibria were possible, including full intertemporal cooperation supported by a social norm based on community punishment of defectors. We report that such social norm did not emerge. Instead, the availability of intrinsically worthless tokens favored the coordination on intertemporal cooperation in ways that networks of strangers were unable to achieve through social norms.

A gut feeling:Noninvasive brain stimulation, gut microbiota and decision-making under risk

The majority of our daily choices include some degree of risk. This dissertation comprises a series of studies that investigate risk-taking behavior through the lens of decision neuroscience, exploring its neural processing from the brain to the gut. The first part includes studies using transcranial alternating current stimulation (tACS) and electroencephalography (EEG) to investigate the role of frontal theta-band activity in the modulation of risk-taking behavior. Part 2 explores the specific roles of the right DLPFC (rDLPFC) and the ventromedial prefrontal cortex (VMPFC) in this type of behavior and demonstrates that both areas are involved in valuation processing and the modulation of risk-taking behavior, reinforcing evidence of a strong functional interplay (Hare et al., 2009; Schiller et al., 2014). Finally, in part 3, the neural basis of risk-taking behavior was explored by looking beyond the central nervous system. The gut microbiota can influence various cognitive processes via the gut-brain axis (GBA). This study explores the effects of a probiotics manipulation on participants’ risk-taking behavior and intertemporal choices. The results show that probiotics led to a relative reduction in risk-taking behavior and increased likelihood of opting for delayed gratification, with reduced discount rates and lower risk proneness. In conclusion, this dissertation provides novel insights into the neural mechanisms underlying risk-taking behavior, both within the central nervous system and including the gut-brain axis as a potential key actor

Interpreting Potential Groundwater Policies through Modeling of Market and Non-Market Benefits and Costs

Current policies leveraging financial incentives and improved irrigation efficiency to mitigate groundwater scarcity have not proven to curtail trends of resource depletion. Groundwater benefits cannot be appropriately valued solely on market forces, and so deeper policy consideration is warranted under a framework that considers the importance of groundwater across all its values to society. Understanding time preferences for groundwater management and preferences for alternative policies is vital to inform efficient policies. Furthermore, climate change remains politically controversial yet has important consequences for critical groundwater resources and their sustainable long-term management. Proliferating policy narratives concerning climate change could influence the way people think about managing groundwater resources. I present three empirical studies that address these issues. Chapter I examines irrigation efficiency technologies for improved outcomes using a market-based, spatially-dynamic optimization model to test the limitations of improvements alone and in tandem with typical environmental policy mechanisms. Improved efficiency induces some producers to plant more of water-intensive crops such as rice, and best-case improvements fail to counter trends of groundwater depletion over a 30-year horizon. Chapter II elicits public willingness to pay (WTP) for long-term groundwater management and for market and non-market groundwater services. I employ time-discounted choice models to endogenously estimate time preferences under different forms of discounting. This is the first non-market valuation to estimate heterogeneity in time preferences using flexible mixing distributions. I find significant WTP for water quality provision, buffer against long-term drought, jobs from agriculture, and provision of wildlife habitat that promotes fishing and duck hunting, while most people display evidence of hyperbolic or quasi-hyperbolic discounting. Individual parameter distributions for WTP and time preferences are not normally distributed. Chapter III continues the Narrative Policy Framework (NPF) tradition to test for systematic influences of narrative frames about climate change on elicited groundwater and policy preferences. In a Choice Experiment (CE), some respondents were exposed to a structuralist, culturally-biased narrative frame about climate change and groundwater resources. Using theories about cultural risk perception and motivated reasoning for systematic evaluation, I find evidence for a cultural incongruency effect but no evidence for a congruency effect. This suggests that people could respond more strongly to incongruence than to congruence in the case of groundwater policy preferences

The Coordination Value of Monetary Exchange: Experimental Evidence

What institutions can sustain cooperation in groups of strangers? Here we study the role of monetary systems. In an experiment, subjects sometimes needed help and sometimes could incur a cost to help an anonymous counterpart. In the absence of money, the intertemporal exchange of help, which could be supported by a norm of community punishment of defectors, did not emerge. Introducing intrinsically worthless tokens substantially altered patterns of behavior. Monetary trade emerged, which increased predictability of play and promoted cooperation when strangers could trade help for a token

Do Losses Matter? The Effect of Information-Search Technologies on Risky Choices

Despite its importance, relatively little attention has been devoted to studying the effects of exposing individuals to digital choice interfaces. In two pre-registered lottery-choice experiments, we administer three information-search technologies that are based on well-known heuristics: in the ABS (alternative-based search) treatment, subjects explore outcomes and corresponding probabilities within lotteries; in the CBS (characteristic-based search) treatment, subjects explore outcomes and corresponding probabilities across lotteries; in the Baseline treatment, subjects view outcomes and corresponding probabilities all at once. We find that (i) when lottery outcomes comprise gains and losses (experiment 1), exposing subjects to the CBS technology systematically makes them choose safer lotteries, compared to the subjects that are exposed to the other technologies, and (ii) when lottery outcomes comprise gains only (experiment 2), the above results are reversed: exposing subjects to the CBS technology systematically makes them choose riskier lotteries. By combining the information-search and choice analysis, we offer an interpretation of our results that is based on prospect theory, whereby the information-search technology subjects are exposed to contributes to determine the level of attention that the lottery attributes receive, which in turn has an effect on the reference point

The Coordination Value of Monetary Exchange: Experimental Evidence

A new behavioral foundation is uncovered for why money promotes impersonal exchange. In an experiment, subjects could cooperate by intertemporally exchanging goods with anonymous opponents met at random. Indefinite repetition supported multiple equilibria, from full defection to the efficient outcome. Introducing the possibility to hold and exchange intrinsically worthless tickets affected outcomes and cooperation patterns. Tickets resembled fiat money, which emerged as a tool for equilibrium selection in the economy. Monetary exchange facilitated coordination on cooperation and redistributed surplus from defectors to cooperators. Treatments where subjects could develop a reputation revealed a limited record-keeping role for monetary exchange.money, cooperation, information, trust, folk theorem, repeated games

Comparing future patterns of energy system change in 2 °C scenarios to expert projections

Integrated assessment models (IAMs) are computer-based instruments used to assess the implications of human activity on the human and earth system. They are simultaneously also used to explore possible response strategies to climate change. As IAMs operate simplified representations of real-world processes within their model structures, they have been frequently criticised to insufficiently represent the opportunities and challenges in future energy systems over time. To test whether projections by IAMs diverge in systematic ways from projections made by technology experts we elicited expert opinion on prospective change for two indicators and compared these with the outcomes of IAM studies. We specifically focused on five (energy) technology families (solar, wind, biomass, nuclear, and carbon capture and storage or CCS) and compared the considered implications of the presence or absence of climate policy on the growth and diffusion of these technologies over the short (2030) to medium (2050) term. IAMs and experts were found to be in relatively high agreement on system change in a business-as-usual scenario, albeit with significant differences in the estimated magnitude of technology deployment over time. Under stringent climate policy assumptions, such as the internationally agreed upon objective to limit global mean temperature increase to no more than 2 °C, we found that the differences in estimated magnitudes became smaller for some technologies and larger for others. Compared to experts, IAM simulations projected a greater reliance on nuclear power and CCS to meet a 2 °C climate target. In contrast, experts projected a stronger growth in renewable energy technologies, particularly solar power. We close by discussing several factors that are considered influential to the alignment of the IAM and expert perspectives in this study