We develop a new version of prospect theory that employs cumulative rather than separable decision weights and extends the theory in several respects. This version, called cumulative prospect theory, applies to uncertain as well as to risky prospects with any number of outcomes, and it allows different weighting functions for gains and for losses. Two principles, diminishing sensitivity and loss aversion, are invoked to explain the characteristic curvature of the value function and the weighting functions. A review of the experimental evidence and the results of a new experiment confirm a distinctive fourfold pattern of risk attitudes: risk aversion for gains and risk seeking for losses of high probability; risk seeking for gains and risk aversion for losses of low probability. Expected utility theory reigned for several decades as the dominant normative and descriptive model of decision making under uncertainty, but it has come under serious question in recent years. There is now general agreement that the theory does not provide an adequate description of individual choice: a substantial body of evidence shows that decision makers systematically violate its basic tenets. Many alternative models have been proposed in response to this empirical challenge (for reviews, see Camerer, 1989; Fishburn, 1988; Machina, 1987). Some time ago we presented a model of choice, called prospect theory, which explained the major violations of expected utility theory in choices between risky prospects with a small number of outcomes (Kahneman and Tversky, 1979; Tversky and Kahneman, 1986). The key elements of this theory are 1) a value function that is concave for gains, convex for losses, and steeper for losses than for gains,

http://psych.fullerton.edu/mbirnbaum/psych466/articles/Tversky_Kahneman_JRU_92.pdf

Advances in prospect theory: cumulative representation of uncertainty

Behavioral scientists routinely publish broad claims about human psychology and behavior in the world's top journals based on samples drawn entirely from Western, Educated, Industrialized, Rich, and Democratic (WEIRD) societies. Researchers - often implicitly - assume that either there is little variation across human populations, or that these "standard subjects" are as representative of the species as any other population. Are these assumptions justified? Here, our review of the comparative database from across the behavioral sciences suggests both that there is substantial variability in experimental results across populations and that WEIRD subjects are particularly unusual compared with the rest of the species - frequent outliers. The domains reviewed include visual perception, fairness, cooperation, spatial reasoning, categorization and inferential induction, moral reasoning, reasoning styles, self-concepts and related motivations, and the heritability of IQ. The findings suggest that members of WEIRD societies, including young children, are among the least representative populations one could find for generalizing about humans. Many of these findings involve domains that are associated with fundamental aspects of psychology, motivation, and behavior - hence, there are no obvious a priori grounds for claiming that a particular behavioral phenomenon is universal based on sampling from a single subpopulation. Overall, these empirical patterns suggests that we need to be less cavalier in addressing questions of human nature on the basis of data drawn from this particularly thin, and rather unusual, slice of humanity. We close by proposing ways to structurally re-organize the behavioral sciences to best tackle these challenges.

/pdf/the-weirdest-people-in-the-world-480wr4m3kb.pdf

The WEIRDest People in the World

This paper discusses the discounted utility (DU) model: its historical development, underlying assumptions, and "anomalies" - the empirical regularities that are inconsistent with its theoretical predictions. We then summarize the alternate theoretical formulations that have been advanced to address these anomalies. We also review three decades of empirical research on intertemporal choice, and discuss reasons for the spectacular variation in implicit discount rates across studies. Throughout the paper, we stress the importance of distinguishing time preference, per se, from many other considerations that also influence intertemporal choices.

/pdf/time-discounting-and-time-preference-a-critical-review-47don96ek5.pdf

Time Discounting and Time Preference: A Critical Review

Virtually all current theories of choice under risk or uncertainty are cognitive and consequentialist. They assume that people assess the desirability and likelihood of possible outcomes of choice alternatives and integrate this information through some type of expectation-based calculus to arrive at decision. The authors propose an alternative theoretical perspective, the risk-as-feelings hypothesis, that highlights the role of affect experienced at the moment of decision making. Drawing on research from clinical, physiological, and other subfield of psychology, they show that emotional reactions to risky situations often drive behavior. The risk-as-feelings hypothesis is shown to explain a wide range of phenomena that have resisted interpretation in cognitive-consequentialist terms.

Risk as Feelings

Virtually all current theories of choice under risk or uncertainty are cognitive and consequentialist. They assume that people assess the desirability and likelihood of possible outcomes of choice alternatives and integrate this information through some type of expectation-based calculus to arrive at a decision. The authors propose an alternative theoretical perspective, the risk-as-feelings hypothesis, that highlights the role of affect experienced at the moment of decision making. Drawing on research from clinical, physiological, and other subfields of psychology, they show that emotional reactions to risky situations often diverge from cognitive assessments of those risks. When such divergence occurs, emotional reactions often drive behavior. The risk-as-feelings hypothesis is shown to explain a wide range of phenomena that have resisted interpretation in cognitive-consequentialist terms.

Risk as feelings.

This article reviews recent developments in the economic theory of individual decision making under risk. Since the 1950s it has been known that individual choices violate the standard model of expected utility in predictable ways. Considerable research effort has now been devoted to the project of developing a superior descriptive model. Following an overview of non-expected utility theories which distinguishes between "conventional" and "non-conventional" approaches, the paper seeks to assess these alternative models in terms of empirical success (using laboratory and field data) and theoretical usefulness. The closing sections reflect on some new directions emerging in this literature.

/pdf/developments-in-non-expected-utility-theory-the-hunt-for-a-4zbkfkszus.pdf

Developments in Non-expected Utility Theory: The Hunt for a Descriptive Theory of Choice under Risk

The Nature of Salience: An Experimental Investigation of Pure Coordination Games

Eight alternative methods of eliciting preferences between money and a consumption good are identified: two of these are standard willingness-to-accept and willingness-to-pay measures. These methods differ with respect to the reference point used and the dimension in which responses are expressed. The loss aversion hypothesis of Tversky and Kahneman's theory of reference-dependent preferences predicts systematic differences between the preferences elicited by these methods. These predictions are tested by eliciting individuals' preferences for two private consumption goods; the experimental design is incentive-compatible and controls for income and substitution effects. The theory's predictions are broadly confirmed.

A Test of the Theory of Reference-Dependent Preferences

https://www.jstor.org/stable/pdfplus/2006657.pdf

Does the Random-Lottery Incentive System Elicit True Preferences? An Experimental Investigation

Since the 1980s, there has been explosive growth in the use of experimental methods in economics, leading to exciting developments in economic theory and policy. Despite this, the status of experimental economics remains controversial. In Experimental Economics, the authors draw on their experience and expertise in experimental economics, economic theory, the methodology of economics, philosophy of science, and the econometrics of experimental data to offer a balanced and integrated look at the nature and reliability of claims based on experimental research.

The authors explore the history of experiments in economics, provide examples of different types of experiments, and show that the growing use of experimental methods is transforming economics into a genuinely empirical science. They explain that progress is being held back by an uncritical acceptance of folk wisdom regarding how experiments should be conducted, a failure to acknowledge that different objectives call for different approaches to experimental design, and a misplaced assumption that principles of good practice in theoretical modeling can be transferred directly to experimental design. Experimental Economics debates how such limitations might be overcome, and will interest practicing experimental economists, nonexperimental economists wanting to interpret experimental research, and philosophers of science concerned with the status of knowledge claims in economics.

Chris Starmer

Papers

Developments in Non-expected Utility Theory: The Hunt for a Descriptive Theory of Choice under Risk

The Nature of Salience: An Experimental Investigation of Pure Coordination Games

A Test of the Theory of Reference-Dependent Preferences

Does the Random-Lottery Incentive System Elicit True Preferences? An Experimental Investigation

Experimental Economics: Rethinking the Rules