The instability of risk preferences: time versus money, sexual motivation, hunger.

Nowadays time is the scarce resource for many consumers. Economists never deal with ‘time poverty’ explicitly since they typically equate time to its monetary equivalent. Individual consumers do not always seem to make their time-related decisions in the same way as their monetary decisions, however. In my PhD project I would like to shed more light on how consumers allocate their scarce resource ‘time’. More specifically, I will investigate whether consumers’ time-related decisions can be described and predicted by prospect theory’s value function. This value function is characterized by three essential features, namely: 1) Referencedependence: the value function is defined over gains and losses relative to a certain reference point. 2) Both the gain and loss functions display diminishing sensitivity (i.e. the value function is S-shaped). 3) Loss aversion (i.e. losses loom larger than gains). By using procedures that have been established in the domain of monetary decision making, I will investigate whether consumers also value their time according to these three characteristics. In doing so, I will explore important boundary conditions to the generalizability of the value function to the time domain.status: publishe

The value of time

Ten studies are used to document that time is valued in accordance with a double-kinked value function. There is a zone of indifference for small time gains (losses), increasing marginal utility (disutility) for moderate time gains (losses), and diminishing marginal utility (disutility) for large time gains (losses). Moderate amounts of time exhibit increasing marginal utility (disutility) because larger blocks of time provide a more diverse set of usage opportunities. It is only when it is difficult to imagine how more (less) time would be beneficial (detrimental) that there is diminishing marginal utility (disutility) for time. Thus, time valuation shows increasing marginal utility when there is a time deficit, but diminishing marginal utility when there is a time surplus. These findings have implications for how other resources might be valued.status: publishe

An appetite for risk? Failure to replicate the effect of hunger cues on risk taking

Ditto et al. (2006) reported that consumers who are exposed to external hunger cues (i.e., scent of freshly baked cookies) are less sensitive to risk information. That is, consumers exposed to hunger cues are as likely to take risks in situations with a high versus low probability of losing. Yet, this result is often cited as evidence that hunger increases risk-taking. This may be due to the fact that Ditto et al. (2006) observed that hunger cues increased risk-taking in situations with a high chance of losing. We attempted to replicate this specific contrast in two studies. In the first study, the risk measure was in the food domain (like in Ditto et al., 2006) and in the second study it was in the financial domain. Yet, we failed to observe a main effect of exposure to external food cues on risk-taking. In addition, as it is an untested assumption in the literature that external (cookie scent) versus internal (not eating for several hours) hunger cues can be used interchangeably, we also checked for a potential moderation by type of hunger cue. We did not observe such a moderation when the risk task involved food outcomes, but we detect such an effect when it involved financial outcomes. These results suggest that the widely held assumptions that (1) hunger or exposure to hunger cues induce risk taking and that (2) internal and external hunger cues are exchangeable should be revisited

What a feeling! Touching sexually laden stimuli makes women seek rewards

We argue that women's previously documented unresponsiveness to sexual primes when making economic decisions may be a consequence of the specific types of primes that have been used (i.e., visual primes). In three studies we show that presenting women with tactile sexual cues does influence their decisions about economic rewards. Similar to the effect found in men, the first study demonstrates that touching a pair of boxer shorts leads to a craving for monetary rewards in women. In the second study it is shown that touching a pair of boxers makes women less loss averse for both money and food. The third study explicitly focuses on the relative effectiveness of tactile versus visual sexual cues in altering women's economic decisions, and reveals that women's willingness-to-pay for economic rewards increases only when the sexual cue is tactile. We suggest that touching (vs. seeing) sexually laden stimuli prompts pre-programmed consummatory Pavlovian responses that promote approaching economic rewards.status: publishe

Time-based versus monetary decision making under risk: An experimental investigation

© 2015 Elsevier B.V.. This paper investigates whether individuals make similar decisions under risk when the outcomes are expressed in time versus monetary units. We address this issue in two studies measuring individual risk preferences and prospect theory parameters (i.e., utility curvature, probability weighting, and loss aversion) for both time and money. In the first (resp., second) study we consider relatively small (resp., large) time and monetary outcomes. We find that individuals hold similar risk preferences for time and money; we also find evidence that "time is money" with regard to the utility curvature for gains, loss aversion, and decision weighting. However, individuals have different valuations of losing time and money. The utility function for small losses of money is more concave and variable than the utility function for small losses of time (Study 1), but the utility function for large losses of time is more concave and variable than that for large losses of money (Study 2). We argue that these results reflect a difference in the perceived slack of the respective resource.publisher: Elsevier articletitle: Time-based versus money-based decision making under risk: An experimental investigation journaltitle: Journal of Economic Psychology articlelink: http://dx.doi.org/10.1016/j.joep.2015.07.003 content_type: article copyright: Copyright © 2015 Elsevier B.V. All rights reserved.status: publishe

On the bright side: The influence of brightness on overall taste intensity perception

Ambient light luminance (i.e., brightness or dimness) is a frequently used tool by managers to enhance the overall ambience in their restaurants. The current research explores how a change in a restaurant's ambient brightness influences the overall taste intensity perception of the food that is being served there. We conducted a between-group experiment in a field setting (i.e., a fine-dining restaurant), where we manipulated the illuminance level of the ambient light (dim vs. bright). Guests were served a dish-tailored to our research question-and asked to evaluate its overall taste intensity. The results demonstrate that guests exposed to the bright ambient light perceived the overall taste of the dish as more intense as opposed to guests exposed to the dim ambient light. The results thus show that modifying the ambient illuminance level in a restaurant does not only affect the overall ambience but also changes the overall taste experience of the food being served. This finding is not only theoretically relevant for research on multisensory integration, but it also provides tools for taste modulation, and-as such-for strategies to decrease salt and sugar consumption among diners

Universal vaccine based on ectodomain of matrix protein 2 of Influenza A: Fc receptors and alveolar macrophages mediate protection

The ectodomain of matrix protein 2 (M2e) of influenza A virus is an attractive target for a universal influenza A vaccine: the M2e sequence is highly conserved across influenza virus subtypes, and induced humoral anti-M2e immunity protects against a lethal influenza virus challenge in animal models. Clinical phase I studies with M2e vaccine candidates have been completed. However, the in vivo mechanism of immune protection induced by M2e-carrier vaccination is unclear. Using passive immunization experiments in wild-type, FcR gamma(-/-), Fc gamma RI-/-, Fc gamma RIII-/-, and (Fc gamma RI, Fc gamma RIII)(-/-) mice, we report in this study that Fc receptors are essential for anti-M2e IgG-mediated immune protection. M2e-specific IgG1 isotype Abs are shown to require functional Fc gamma RIII for in vivo immune protection but other anti-M2e IgG isotypes can rescue Fc gamma RIII-/- mice from a lethal challenge. Using a conditional cell depletion protocol, we also demonstrate that alveolar macrophages (AM) play a crucial role in humoral M2e-specific immune protection. Additionally, we show that adoptive transfer of wild-type AM into (Fc gamma RI, Fc gamma RIII)(-/-) mice restores protection by passively transferred anti-M2e IgG. We conclude that AM and Fc receptor-dependent elimination of influenza A virus-infected cells are essential for protection by anti-M2e IgG