In recent years, descriptive models of risky choice have incorporated features that reflect the importance of particular outcome values in choice. Cumulative prospect theory (CPT) does this by inserting a reference point in the utility function. SP/A (security-potential/aspiration) theory uses aspiration level as a second criterion in the choice process. Experiment 1 compares the ability of the CPT and SP/A models to account for the same within-subjects data set and finds in favor of SP/A. Experiment 2 replicates the main finding of Experiment 1 in a between-subjects design. The final discussion brackets the SP/A result by showing the impact on fit of both decreasing and increasing the number of free

Security is both a feeling and a reality. And they’re not the same. The reality of security is mathematical, based on the probability of different risks and the effectiveness of different countermeasures. We can calculate how secure your home is from burglary, based on such factors as the crime rate in the

of the process) for helpful comments. 1 Behavioral economics increases the explanatory power of economics by providing it with more realistic psychological foundations. This book consists of representative recent articles in behavioral economics. 1 This chapter is intended to provide an introduction to the approach and methods of behavioral economics, and to some of its major findings, applications, and promising new directions. It also seeks to fill some unavoidable gaps in the chapters ’ coverage of topics. What Behavioral Economics Tries To Do At the core of behavioral economics is the conviction that increasing the realism of the psychological underpinnings of economic analysis will improve economics on its own terms--generating theoretical insights, making better predictions of field phenomena, and suggesting better policy. This conviction does not imply a wholesale rejection of the neoclassical approach to economics based on utility maximization, equilibrium, and efficiency. The neoclassical approach is useful because it provides economists with a theoretical framework that can be applied to almost any form of economic (and even non-economic) behavior, and it makes refutable predictions. Many of these predictions are tested in the chapters of this book, and rejections of those predictions suggest new theories. Most of the papers modify one or two assumptions in standard theory in the direction of greater psychological realism. Often these departures are not radical at all because they relax simplifying assumptions that are not central to the economic approach. For example, there is nothing in core neoclassical theory that specifies that people should not care about fairness, that they should weight risky outcomes in a linear fashion, or that they must discount the future exponentially at a constant rate. 2 Other assumptions simply acknowledge human limits on 1 Since it is a book of advances, many of the seminal articles which influenced those collected here are not included, but are noted below and are widely reprinted elsewhere.

The current research studies the dynamics of one instance of dynamic pricing-- group-buying discounts--used by MobShop.com, whose products ’ selling prices drop as more buyers place their orders. We use an econometric model to analyze changes in the number of orders for Mobshop-listed products over various periods of time. We find that the number of existing orders has a significant positive effect on new orders placed during each 3-hour period, indicating the presence of a positive participation externality effect. We also find evidence for expectations of falling prices, a price drop effect. The results also reveal a significant ending effect, as more orders were placed during the last 3-hour period of the auction cycles.

This study tests between two modern theories of decision making. Rank- and sign-dependent utility (RSDU) models, including cumulative prospect theory (CPT), imply stochastic dominance and two cumulative independence conditions. Configural weight models, with parameters estimated in previous research, predict systematic violations of these properties for certain choices. Experimental data systematically violate all three properties, contrary to RSDU but consistent with configural weight models. This study also tests whether violations of stochastic dominance can be explained by violations of transitivity. Violations of transitivity may be evidence of a dominance detecting mechanism. Although some transitivity violations were observed, most choice triads violated stochastic dominance without violating transitivity. Judged differences between gambles were not consistent with the CPT model. Data were not consistent with the editing principles of cancellation and combination. The main findings are interpreted in terms of coalescing, the principle that equal outcomes can be combined in a gamble by adding their probabilities. RSDU Address correspondence and reprint requests to Michael H. Birnbaum, Department of Psychology,

Abstract not found

A referenc'8---bcb' generalisation ofsubjecbw8 expecc utility theory is presented. In this theory,preferencb betweenacw depend both on finaloutcD---: and onreferenc points (whic may e uncL':bw acL' It iscD'GPGbwD:FL y a set of axioms in a Savage-style framework. A restricDF form of the theory separates attitudes to end states(encsb8 in a `satisfacF---L funcfacF from attitudes to gains and losses ofsatisfacD---qP Given weak additional assumptions, the restricbw theoryexcrybD ccry ofcb8'---q explains o served disparities etween willingness-to-pay and willingness-to-acbD' valuations of lotteries, and predicD preferenc reversal.

This paper presents a model of portfolio choice and stock trading volume with lossaverse investors. The demand function for risky assets is discontinuous and non-monotonic: as wealth rises beyond a threshold investors follow a generalized portfolio insurance strategy. This behavior is consistent with the evidence in favor of the disposition effect. In addition, loss-averse investors will not hold stocks unless the equity premium is quite high. The elasticity of the aggregate demand curve changes substantially, depending on the distribution of wealth across investors. In an equilibrium setting the model generates positive correlation between trading volume and stock return volatility, but suggests that this relationship should be non-linear.

A long-running difficulty with conventional game theory has been how to modify it to accommodate the bounded rationality of all real-world players. A recurring issue in statistical physics is how best to approximate joint probability distributions with decoupled (and therefore far more tractable) distributions. This paper shows that the same information theoretic mathematical structure, known as Product Distribution (PD) theory, addresses both issues. In this, PD theory not only provides a principled formulation of bounded rationality and a set of new types of mean field theory in statistical physics; it also shows that those topics are fundamentally one and the same. 1

Prospect theory and loss aversion play a dominant role in behavioral finance. In this paper we derive closed-form solutions for optimal portfolio choice under loss aversion. When confronted with gains a loss averse investor behaves similar to a portfolio insurer. When confronted with losses, the investor aims at maximizing the probability that terminal wealth exceeds his aspiration level. Our analysis indicates that a representative agent model with loss aversion cannot resolve the equity premium puzzle. We also extend the martingale methodology to allow for more general utility functions and provide a simple approach to incorporate skewed and fat-tailed return distributions.