Saving is viewed as deferred consumption and studied within the framework of intertemporal choice. The literature, drawn from psychology, economics and economic psychology, suggests that whilst there have been many theoretical references to the relationship between individual differences associated with intertemporal decision-making and saving, and these individual difference variables have been studied in relation to other behaviour, there is a lack of empirical research investigating their relationship with saving. The particular variables of interest are delay of gratification, time preference (impatience), self control, impulsiveness and consideration of future consequences. This thesis presents a series of empirical studies which used carefully constructed or selected measures to investigate the relationship between individual differences associated with intertemporal decision-making and saving. A variety of methods were used. The first two studies measured delay of gratification using a behavioural choice paradigm and investigated its relationship with saving. The next three studies measured a construct known as the consideration of future consequences and examined its relationship with saving. In-depth interviews, focusing on impulsiveness and impatience provided a more realistic investigation of the personality structure of delay, and aided the development of quantitative measures of impulsiveness. Secondary analysis of Dutch panel data enabled the hypotheses to be tested with a larger dataset and shifts in assets as a measure of saving. The group of studies culminated in a postal survey of married couple households, allowing a multivariate investigation of all the individual difference constructs which had been developed and investigated. This final study also addressed issues such as the relative influence of psychological data from both spouses in a decision-making unit. The results are discussed throughout the thesis in the light of their implications for psychology, economics, policy-making and marketing, as well as for economic psychology. The main contributions are some new measures of theoretically relevant individual difference constructs, which will require further testing in order to prove their worth

Risky intertemporal choice is a fairly new topic in the realm of behavioral economics that involves examining the interactions between individuals’ time and risk preferences. Previous research has looked at the gains and mixed domain, but little to no research has been done in the loss domain. This study aims to fill this gap by examining how people respond to risky gambles in the loss domain given real world time delays. The thesis focuses on changes in attitudes towards risk caused by temporal distance rather than how people discount risky prospects. Based on Construal Level Theory we predict that there will be a greater focus on outcomes over probabilities in delayed gambles compared to immediate ones, and hence, individuals will become more risk-averse for delayed gambles that are in the loss domain. We conducted two experiments to test this prediction. Results revealed that while subjects in the immediate resolution group were significantly more risk-seeking than future resolution groups in both experiments, the difference in risk attitudes between two delayed resolutions depend on how big the difference between two delays is.

Risky intertemporal choice is a fairly new topic in the realm of behavioral economics that involves examining the interactions between individuals’ time and risk preferences. Previous research has looked at the gains and mixed domain, but little to no research has been done in the loss domain. This study aims to fill this gap by examining how people respond to risky gambles in the loss domain given real world time delays. The thesis focuses on changes in attitudes towards risk caused by temporal distance rather than how people discount risky prospects. Based on Construal Level Theory we predict that there will be a greater focus on outcomes over probabilities in delayed gambles compared to immediate ones, and hence, individuals will become more risk-averse for delayed gambles that are in the loss domain. We conducted two experiments to test this prediction. Results revealed that while subjects in the immediate resolution group were significantly more risk-seeking than future resolution groups in both experiments, the difference in risk attitudes between two delayed resolutions depend on how big the difference between two delays is.

Thesis submitted by Jinrui Pan for the Degree of Doctor of Philosophy in the University of Manchester, and entitled, “Time and Risk Preferences: Theoretical Models and Applications.” Date of submission 2014.This thesis makes contributions to two important areas of behavioural economics, namely individual decision making over time and under risk. Following the Introduction, Chapter 2 presents a new discounting function for analysing intertemporal choice. Liminal discounting, the model developed here, generalises exponential discounting in a parsimonious way. It allows for well-known departures, whilst maintaining its elegance and tractability. It also can be seen as an extension of quasi-hyperbolic discounting to continuous time. A liminal discounter has a constant rate of time preference before and after some threshold time; the liminal point. A preference foundation is provided, showing that the liminal point is derived endogenously from behaviour. Chapter 3 proposes an axiomatic model featuring a differential treatment of attitudes towards risk and time. Such distinction has been strongly suggested by experimental research when studying intertemporal choice, since the future is inherently risky. In the proposed model, non-linear probability distortions are incorporated into a dynamic model with discounted utility. Time is captured by a general discounting function independent of probabilities and outcomes. Utility of outcomes is captured by standard vNM utility independent of time. A two-parameter probability weighting function captures intertemporal probabilistic risk attitudes, with one parameter being constant over time, the other being time-dependent. An index of optimism is derived that depends on both parameters, which allows to model the observed high risk tolerance for delayed lotteries. Further, a preference foundation is provided. Interestingly, the model allows behaviour to be consistent with discounted expected utility, when risk is sufficiently distant from the present.

Humans and other animals discount the value of future rewards, a phenomenon known as delay discounting. Individuals vary widely in the extent to which they discount future rewards, and these tendencies have been associated with important life outcomes. Recent studies have demonstrated that imagining the future reduces subsequent discounting behavior, but no research to date has examined whether a similar principle applies at the trait level, and whether training visualization changes discounting. The current study examined if individual differences in visualization abilities are linked to individual differences in discounting and whether practicing visualization can change discounting behaviors in a lasting way. Participants (n = 48) completed the Vividness of Visual Imagery Questionnaire (VVIQ) and delay discounting task and then underwent a 4-week intervention consisting of visualization training (intervention) or relaxation training (control). Contrary to our hypotheses, participants who reported greater visualization abilities (lower scores) on the VVIQ were higher discounters. To further examine this relationship, an additional 106 participants completed the VVIQ and delay discounting task. In the total sample (n = 154), there was a significant negative correlation between VVIQ scores and discount rates, showing that individuals who are better visualizers are also higher discounters. Consistent with this relationship but again to our surprise, visualization training tended, albeit weakly, to increase discount rates, and those whose VVIQ decreased the most were those whose discount rates increased the most. These results suggest a novel association between visualization abilities and delay discounting.

The focus of this thesis is to explore the impact of positive affective state and mood salience on intertemporal decision making. We found that positive affect significantly influence intertemporal preference. We also found that when current mood becomes salient to the decision maker, the direction of preference changes. Specifically, we hypothesized and found that individuals with positive mood are more likely to choose the later larger (long term) rewards than the individuals with a neutral mood. We discuss three factors that could explain choice behaviour in such situations. These factors are the willingness to maintain positive mood, temporal orientation and risk perception, and increase in the level of dopamine in brain. Moreover, our results indicate that when current positive mood is salient, individuals become more concerned about their affective state, and are more likely to engage in affect regulation, and as a result, more likely to prefer the sooner smaller (immediate) rewards. These findings suggest that experiencing positive affect would increase patience and self-control. However, this is the case when the level of mood salience is not high. When individuals’ attention is directed to their emotional states, they tend to choose sooner smaller rewards that could assist them in keeping their good mood and avoiding negative feelings.

The focus of this thesis is to explore the impact of positive affective state and mood salience on intertemporal decision making. We found that positive affect significantly influence intertemporal preference. We also found that when current mood becomes salient to the decision maker, the direction of preference changes. Specifically, we hypothesized and found that individuals with positive mood are more likely to choose the later larger (long term) rewards than the individuals with a neutral mood. We discuss three factors that could explain choice behaviour in such situations. These factors are the willingness to maintain positive mood, temporal orientation and risk perception, and increase in the level of dopamine in brain. Moreover, our results indicate that when current positive mood is salient, individuals become more concerned about their affective state, and are more likely to engage in affect regulation, and as a result, more likely to prefer the sooner smaller (immediate) rewards. These findings suggest that experiencing positive affect would increase patience and self-control. However, this is the case when the level of mood salience is not high. When individuals’ attention is directed to their emotional states, they tend to choose sooner smaller rewards that could assist them in keeping their good mood and avoiding negative feelings.

Why is it difficult to save for a pension or maintain a healthy diet? Choosing between options that have future or delayed consequences presents a challenge for a decision maker. When faced with such intertemporal choices the tendency to favour choices with immediate or short term outcomes, otherwise known as delay discounting, can lead to suboptimal consequences in the long-term. However, the mechanisms underlying the devaluation of future outcomes are poorly understood. This is due to the lack of a consistent framework for the representation of delays and delayed outcomes. One perspective is to represent delays as uncertainty. However, current conceptions of uncertainty are limited, by and large, to the dimension of probability, and are therefore inadequate. This thesis adopts a delay discounting model and emphasises different types of uncertainties within choice. Unifying these components, a framework that considers intertemporal choice as decision making under uncertainty is proposed. A series of behavioural and electrophysiological studies is presented to demonstrate that: it is the perceived uncertainty about 'if' and 'when' outcomes occur that contributes to behavioural discounting (chapters 2 and 3); the perception and evaluation of 'what' is delayed is underlined by emotional processes (chapter 4); and that generally, uncertainties about 'if' and 'what' outcomes differentially characterise risky and impulsive choices (chapter 5), and can be distinguished in terms of their informational qualities (chapter 6). Collectively, these findings present a deconstruction of uncertainty into components of 'if', 'what' and 'when', that could be mapped to delayed outcomes. I discuss them within the context of judgement and decision making, individual differences, and neural aspects of reward processing. These results allow me to argue that 1) all decision making is a process of information availability; 2) behaviour is motivated to reduce uncertainty; 3) choice is the manifestation of acquired information gathered from a decision-maker's internal and/or external environment. In conclusion, this thesis demonstrates that decision making under uncertainty can be qualified beyond a single dimension of probability; and that uncertainty can be characterised as a state of incomplete information about 'if' 'what' and 'when' outcomes will occur. Accordingly, intertemporal and risky choices can be accommodated within a single framework, subject to the same cognitive and neural processes. Consequently, this framework allows for the design of behavioural interventions that specifically target reducing uncertainties of 'if', 'what' or 'when'.

O córtex orbitofrontal é apontado como uma estrutura fundamental para a tomada de decisão baseada em valor. Acredita-se que sua função envolva a valoração de recompensas a partir da integração de informações sensoriais e memória, a fim de comparar custos e benefícios. Resultados conflitantes sobre os efeitos da lesão do córtex orbitofrontal em tarefas de escolha intertemporal geram questionamentos sobre o nível de especialização de sua função. O presente estudo almeja testar a hipótese de que a participação do córtex orbitofrontal no desempenho de tarefa de escolha intertemporal depende da experiência dos animais com a tarefa em relação ao momento da lesão. Para isto foi utilizada uma tarefa de escolha intertemporal em que os animais deveriam escolher entre dois reforços distintos, um deles menor e entregue imediatamente após a resposta, e o outro maior porém entregue após um determinado tempo de espera após a resposta. Foram incluídos quatro grupos, dois experimentais envolvendo lesão neurotóxica do córtex orbitofrontal e dois controle-operados submetidos a procedimentos idênticos, exceto pela indução de lesão (os grupos controle foram, posteriormente a análises dos resultados comportamentais e constatada ausência de diferença, fundidos num único grupo controle). Um grupo experimental e um correspondente grupo controle foram submetidos a neurocirurgia antes da exposição a 15 sessões de treino na tarefa. Um outro grupo experimental e seu correspondente controle foram submetidos a treinamento similar, porém, depois da neurocirurgia. Posteriormente, todos os animais foram submetidos a 10 sessões adicionais de treino na mesma tarefa e, a seguir, a outras 10 sessões de treino de reversão, em que os locais previamente associados aos esquemas de reforço foram invertidos. Os resultados revelaram que todos os grupos se comportaram de maneira semelhante nas diferentes fases experimentais, independente do momento de realização da lesão ou mesmo da própria lesão, indicando que o córtex orbitofrontal intacto não é necessário para a aquisição e o desempenho da tarefa de escolha intertemporal. Esses resultados levam a conclusão de que danos seletivos do córtex orbitofrontal não geram prejuízos no desempenho de escolhas intertemporais / The orbifrontal cortex is pointed out as a fundamental structure for value-based decision making. It is believed that its function involves the valuation of rewards from the integration of sensory information and memory in order to compare costs and benefits. Conflicting results on the effects of the orbifrontal cortex lesion on tasks of intertemporal choice bring about questions on the level of specialization of its function. The purpose of the present study is to test the hypothesis that the participation of the orbifrontal cortex in the task performance of intertemporal choice depends on the experience of the animal with the task in relation to the moment of injury. For this, an intertemporal choice task was used in which the animals had to choose between two distinct reinforcements, one smaller and delivered immediately after the response and the other larger but delivered after a certain waiting time after the response. Four groups were included, two experimental groups involving neurotoxic injury and two control groups, submitted to identical procedures, except for the induction of lesion (the control groups were, after an analysis of behavioral results and found no difference, merged into a single group control) an experimental group and a corresponding control group underwent neurosurgery before being exposed to 15 training tasks sessions. Another experimental group and its corresponding control underwent similar training, yet, after neurosurgery. Afterward, all the animals were submitted to 10 additional training sessions on the same task and later to another 10 reversal sessions, in which the sites previously associated to the reinforcement schemes were inverted. The results revelead that all groups behaved similarly in the different experimental phases regardless the time of injury or even the lesion itself, showing that the intact orbifrontal cortex is not necessary for the acquisition and performance of the task of intertemporal choice. These results lead to the conclusion that selective orbifrontal cortex damages do not generate losses in the performance of intertemporal choices

Natural aging leads to substantial brain changes. These biological changes can, and often do, precede changes in affect, cognition, and behavior. Even subtle changes, for example in affective experience, can create problematic outcomes in day-to-day emotion regulation and decision-making. For example, poor emotion regulation may lead an individual to fall prey to an emotionally potent scam. Similarly, an overly positive individual may not fully attend to or consider potentially negative future outcomes when faced with a decision. This work characterizes changes in affect across the lifespan, and how affect corresponds to brain function, as indexed by the blood oxygen dependent signal, during tasks taxing emotion regulation and decision-making functions. I predicted that age would correlate with greater positive relative to negative emotions and with a more global (i.e., less specific and less complex) representation of emotions. The former predicted pattern indicates increased "affective optimization" and the latter indicates reduced "affective complexity." I predicted that affective optimization and complexity would correlate with brain function during emotion regulation and decision-making. I used time-based experience sampling, self-reported affect, implicit measures of affect, and performance based measures of affect to determine the associations between age and affective optimization and complexity. Results show that age negatively correlates with affective complexity. Specifically, older age was associated with less negative affect complexity, less positive emotion regulation, less affective awareness. Also, older age corresponded to lower levels of negative affect, as indexed by their experiences and an implicit measure of affect. Next, I examined emotion regulation using a cognitive reappraisal task. I found that older age was associated with less successful reappraisal of negative and positive affect. I also found individual differences in the ventromedial prefrontal cortex among older adults during emotion regulation. Lastly, I examined decision-making patterns using an intertemporal choice task. I found that younger adults’ experienced affect aligned more closely with their decision patterns. Among older adults, affective acceptance correlated with individual differences in the striatum and insula. Taken together, these results support the idea that lower levels of affective competence, rather than higher levels, characterize older age. Also, individual differences in affect parallel individual differences in brain function in the somatic marker circuitry. This suggests possible deficits in interpreting visceral information important to emotion regulation and decision-making. The findings from this work will be important for understanding why some older adults are more susceptible to scams, fraud, and decision-making problems.