Cumulative weighing of time in intertemporal tradeoffs

We examine preferences for sequences of delayed monetary gains. In the experimental literature, two prominent models have been advanced as psychological descriptions of preferences for sequences. In one model, the instantaneous utilities of the outcomes in a sequence are discounted as a function of their delays, and assembled into a discounted utility of the sequence. In the other model, the ccumulated utility of the outcomes in a sequence is considered along with utility or disutility from improvement in outcome utilities and utility or disutility from the spreading of outcome utilities. Drawing on three threads of evidence concerning preferences for sequences of monetary gains, we propose that the accumulated utility of the outcomes in a sequence is traded off against the duration of utility accumulation. In our first experiment, aggregate choice behavior provides qualitative support for the tradeoff model. In three subsequent experiments, one of which incentivized, disaggregate choice behavior provides quantitative support for the tradeoff model in Bayesian model contests. The third experiment addresses one thread of evidence that motivated the tradeoff model: When, in the choice between two single dated outcomes, it is conveyed that receiving less sooner means receiving nothing later, preference for receiving more later increases, but when it is conveyed that receiving more later means receiving nothing sooner, preference is left unchanged. Our results show that this asymmetric hidden-zero effect is indeed driven by those supporting the tradeoff model. The tradeoff model also accommodates all remaining evidence on preferences for sequences of monetary gains

Neuroeconomics: How Neuroscience Can Inform Economics

Neuroeconomics uses knowledge about brain mechanisms to inform economic analysis, and roots economics in biology. It opens up the "black box" of the brain, much as organizational economics adds detail to the theory of the firm. Neuroscientists use many tools— including brain imaging, behavior of patients with localized brain lesions, animal behavior, and recording single neuron activity. The key insight for economics is that the brain is composed of multiple systems which interact. Controlled systems ("executive function") interrupt automatic ones. Emotions and cognition both guide decisions. Just as prices and allocations emerge from the interaction of two processes—supply and demand— individual decisions can be modeled as the result of two (or more) processes interacting. Indeed, "dual-process" models of this sort are better rooted in neuroscientific fact, and more empirically accurate, than single-process models (such as utility-maximization). We discuss how brain evidence complicates standard assumptions about basic preference, to include homeostasis and other kinds of state-dependence. We also discuss applications to intertemporal choice, risk and decision making, and game theory. Intertemporal choice appears to be domain-specific and heavily influenced by emotion. The simplified ß-d of quasi-hyperbolic discounting is supported by activation in distinct regions of limbic and cortical systems. In risky decision, imaging data tentatively support the idea that gains and losses are coded separately, and that ambiguity is distinct from risk, because it activates fear and discomfort regions. (Ironically, lesion patients who do not receive fear signals in prefrontal cortex are "rationally" neutral toward ambiguity.) Game theory studies show the effect of brain regions implicated in "theory of mind", correlates of strategic skill, and effects of hormones and other biological variables. Finally, economics can contribute to neuroscience because simple rational-choice models are useful for understanding highly-evolved behavior like motor actions that earn rewards, and Bayesian integration of sensorimotor information

In sickness and in health ... risk-sharing within households in rural Ethiopia

To investigate risk-sharing within the household, we model nutritional status as a durable good and we look at the consequences of individual health shocks. For household allocation to be pareto-efficient, households should pool shocks to income. We also investigate whether households can smooth nutritional levels over time. Using data from rural Ethiopia on adult nutritional status, we find that poor households are affected by idiosyncratic agricultural shocks, while richer households are more successful in smoothing nutritional levels. All individuals adjust to predictable changes in earnings and the nutritional status of poor individuals is responsive to seasonal food price fluctuations. Poor southern households are not sharing risk; women in these households bear the brunt of adverse shocks. Finally, we look at the role of inside and outside options in determining the intrahousehold allocation of nutrition of married couples. We find that wives’ relative position improves with a smaller age gap between partners, in younger marriages, as well as by favourable customary laws on settlements upon divorce – but the most important variable affecting allocation is household wealth.

Chronic Poverty and All That: The Measurement of Poverty over Time

We explore how to measure poverty over time, by focusing on trajectories of poverty rather than poverty at a particular point in time. We consider welfare outcomes over a period in time, consisting of a number of spells. We offer a characterization of desirable properties for measuring poverty across these spells, as well as an explicit discussion of three issues. First, should there be scope for compensation so that a poor spell can be compensated for by a non-poor spell? Second, is there scope for discounting or should all spells be equally valued? Third, does the actual sequence of poor spells matter, for example whether they are consecutive or not? We offer a number of measures that implicitly offer different answers to these questions, in a world of certainty. Finally, we also offer an extension towards a forward-looking measure of vulnerability, defined as the threat of poverty over time, that incorporates risk. An application to data from Ethiopia shows that especially the assumption of compensation results in different inference on poverty.poverty, chronic poverty, poverty dynamics, Ethiopia

The Investment Incentives Effects of Land Use Regulations

This paper provides an overview and synthesis of the results from recent studies of how different types of land use regulations affect land development incentives. The presentation is nontechnical and focuses on uncovering general principles for the dynamic effects of such policies. It explains why the risk of regulation leads to faster development of unregulated land and how the effect on structural densities reflects the underlying pattern of growth in the demand for land by competing uses. It also discusses how the general pattern of timing and density responses for regulated property reflect the same growth patterns in demand. Working Paper No. 03-0

The value of nothing : asymmetric attention to opportunity costs drives intertemporal decision making

This paper proposes a novel account of why intertemporal decisions tend to display impatience: People pay more attention to the opportunity costs of choosing larger, later rewards than to the opportunity costs of choosing smaller, sooner ones. Eight studies show that when the opportunity costs of choosing smaller, sooner rewards are subtly highlighted, people become more patient, whereas highlighting the opportunity costs of choosing larger, later rewards has no effect. This pattern is robust to variations in the choice task, to the participant population, and is observed for both incentivized and hypothetical choices. We argue that people are naturally aware of the opportunity costs associated with delayed rewards, but pay less attention to those associated with taking smaller, sooner ones. We conclude by discussing implications for theory and policy

The Impact of Institutions on the Decision How to Decide

The human mind is not a general problem solving machine. Instead of deliberately, consciously and serially processing the available information, men can rely on routines, rules, roles or affect for the purpose. They can bring in technology, experts or groups. For all of these reasons, men have a plurality of problem solving modes at their disposition. Often, the meta-choice of problem solving mode matters for behavioural output. Some performance standards are only to be met if a certain problem solving mode is used, like a well-established skill. Other requirements are easier to fulfil with some problem solving modes. This explains why institutions frequently impact on the choice of problem solving mode. To show how institutions are able to do that, a model of problem solving modes is developed. It allows to systematise the access points for institutional intervention.Decision Making, Problem Solving, Institutions

Search predicts and changes patience in intertemporal choice

Intertemporal choice impacts many important outcomes, such as decisions about health, education, wealth, and the environment. However, the psychological processes underlying decisions involving outcomes at different points in time remain unclear, limiting opportunities to intervene and improve people’s patience. This research examines information-search strategies used during intertemporal choice and their impact on decisions. In experiment 1, we demonstrate that search strategies vary substantially across individuals. We subsequently identify two distinct search strategies across individuals. Comparative searchers, who compare features across options, discount future options less and are more susceptible to acceleration versus delay framing than integrative searchers, who integrate the features of an option. Experiment 2 manipulates search using an unobtrusive method to establish a causal relationship between strategy and choice, randomly assigning participants to conditions promoting either comparative or integrative search. Again, comparative search promotes greater patience than integrative search. Additionally, when participants adopt a comparative search strategy, they also exhibit greater effects of acceleration versus delay framing. Although most participants reported that the manipulation did not change their behavior, promoting comparative search decreased discounting of future rewards substantially and speeded patient choices. These findings highlight the central role that heterogeneity in psychological processes plays in shaping intertemporal choice. Importantly, these results indicate that theories that ignore variability in search strategies may be inadvertently aggregating over different subpopulations that use very different processes. The findings also inform interventions in choice architecture to increase patience and improve consumer welfare

The Unified Tradeoff Model

Evidence is steadily mounting that attribute-based models offer a more accurate description of intertemporal choices than traditional alternative-based models. Among the attribute-based models, the tradeoff model offers the broadest coverage of research findings, but at the cost of considerable complexity: There now are various instantiations of the model dealing with partially overlapping universes of choice options and preference patterns. Moreover, there are reports of preference patterns in intertemporal decisions about monetary losses that contradict all attribute-based models proposed so far. Taking stock of these core challenges, and all other evidence, we develop an account of intertemporal choice, the Unified Tradeoff Model, that is simpler, yet more comprehensive, than all currently available instantiations of the tradeoff model taken together. It borrows extensively from its predecessors, but it introduces a new element, time bias, that enables it to accommodate an extraordinarily broad range of preference patterns, and also generate new predictions that contradict all existing models of intertemporal choice. We report four studies that test and confirm its predictions regarding delay, interval, sign, and magnitude dependence in choices between single-dated outcomes, and a fifth study that tests and confirms its predictions regarding the relation between delay preference in choices that only involve single-dated payments and duration preference in choices that also involve sequences of payments. Having subjected the Unified Tradeoff Model to an elevated risk of disconfirmation, we discuss its parsimony and scope in relation to yet other phenomena, most notably, preference patterns in consumption decisions, the final frontier for attribute-based models

Precaution: principles and practice in Australian environmental and natural resource management

Precaution: principles and practice in Australian environmental and natural resource management by Deborah Peterson, was presented as the Presidential Address to the 50th Annual Australian Agricultural and Resource Economics Society Conference, Manly, New South Wales, 8 - 10 February 2006. Since the late 1980s, the concept of precaution has been incorporated into numerous international agreements and laws, as well as in domestic statutes and policies in many countries. This paper examines the international emergence of the concept and its application in Australia. Despite rapid growth in adoption of the so-called "precautionary principle," the concept remains highly controversial, and its success in terms of improving environmental and natural resource management has been questioned. This paper argues that implementation guidelines are essential to ensure that precautionary decision making is consistent with good decision making principles, and to avoid unnecessary costs and the potential for perverse outcomes. Economists have an important role in contributing to these guidelines and in developing techniques for incorporating uncertainty into decision making. The views expressed in this paper do not necessarily reflect those of the Australian Government or the Productivity Commission.Resource /Energy Economics and Policy,