Social Comparisons in Ultimatum Bargaining

Experiments are used to examine the effects of social comparisons in ultimatum bargaining. We inform responders about the average offer before they decide whether to accept or reject their specific offer. This significantly increases offers and offer‐specific rejection probabilities. For comparison, we consider another change in informational conditions: telling responders the total pie is $30—ex ante it was either $15 or $30—affects offers and rejection probabilities roughly as much. Our results are consistent with people’s dislike for deviations from the norm of equity but inconsistent with fairness theories, where people dislike income disparity between themselves and their referents.     

Overreaction to Fearsome Risks

When risks threaten, cognitive mechanisms bias people toward action or inaction. Fearsome risks are highly available. The availability bias tells us that this leads people to overestimate their frequency. Therefore, they also overreact to curtail the likelihood or consequences of such risks. More generally, fear can paralyze efforts to think clearly about risks. We draw on a range of environmental risks to show the following: (1) Fear leads us to neglect probability of occurrence; (2) As fearsome environmental risks are usually imposed by others (as externalities), indignation stirs excess reaction; (3) We often misperceive or miscalculate such risks. Two experiments demonstrate probability neglect when fearsome risks arise: (a) willingness-to-pay to eliminate the cancer risk from arsenic in water (described in vivid terms) did not vary despite a 10-fold variation in risk; (b) the willingness-to-accept price for a painful but non dangerous electric shock did not vary between a 1 and 100% chance. Possible explanations relate to the role of the amygdala in impairing cognitive brain function. Government and the law, both made by mortals and both responding to public pressures, similarly neglect probabilities for fearsome risks. Examples relating to shark attacks, Love Canal, alar and terrorism are discussed.     

The online laboratory: conducting experiments in a real labor market

Online labor markets have great potential as platforms for conducting experiments. They provide immediate access to a large and diverse subject pool, and allow researchers to control the experimental context. Online experiments, we show, can be just as valid—both internally and externally—as laboratory and field experiments, while often requiring far less money and time to design and conduct. To demonstrate their value, we use an online labor market to replicate three classic experiments. The first finds quantitative agreement between levels of cooperation in a prisoner’s dilemma played online and in the physical laboratory. The second shows—consistent with behavior in the traditional laboratory—that online subjects respond to priming by altering their choices. The third demonstrates that when an identical decision is framed differently, individuals reverse their choice, thus replicating a famed Tversky-Kahneman result. Then we conduct a field experiment showing that workers have upward-sloping labor supply curves. Finally, we analyze the challenges to online experiments, proposing methods to cope with the unique threats to validity in an online setting, and examining the conceptual issues surrounding the external validity of online results. We conclude by presenting our views on the potential role that online experiments can play within the social sciences, and then recommend software development priorities and best practices.     

The value of reputation on eBay: A controlled experiment

We conducted the first randomized controlled field experiment of an Internet reputation mechanism. A high-reputation, established eBay dealer sold matched pairs of lots—batches of vintage postcards—under his regular identity and under new seller identities (also operated by him). As predicted, the established identity fared better. The difference in buyers’ willingness-to-pay was 8.1% of the selling price. A subsidiary experiment followed the same format, but compared sales by relatively new sellers with and without negative feedback. Surprisingly, one or two negative feedbacks for our new sellers did not affect buyers’ willingness-to-pay. JEL Classification D82 · L14 · Z13     

High Stakes Decision Making: Normative,Descriptive and Prescriptive Considerations

This paper reviews the state of the art of research on individual decision-making in high-stakes, low-probability settings. A central theme is that resolving high-stakes decisions optimally poses a formidable challenge not only to naïve decision makers, but also to users of more sophisticated tools, such as decision analysis. Such decisions are difficult to make because precise information about probabilities is not available, and the dynamics of the decision are complex. When faced with such problems, naïve decision-makers fall prey to a wide range of potentially harmful biases, such as failing to recognize a high-stakes problem, ignoring the information about probabilities that does exist, and responding to complexity by accepting the status quo. A proposed agenda for future research focuses on how the process and outcomes of high-stakes decision making might be improved.     

Communicating the health effects of consumer products: The case of moderate alcohol consumption and coronary heart disease

Moderate consumption of alcoholic beverages (MAC) has been estimated to significantly reduce the risk of myocardial infarction. This paper examines effective ways to communicate this information to guide individuals and their physicians, who must weight personal benefits and costs when deciding about drinking. It argues that presenting a scalar representation of the effect, life years saved, is much more effective than the ways such information is currently communicated. A simulation using data from the Framingham Heart Study and a conservative estimate of the effect of MAC calculates age-specific gains in mortality, and survival gains from MAC. They are roughly 0.75 and 0.63 years, respectively, for men and women ages 21–50. Any MAC decision should weigh the benefits of cardiac risk reduction against possible financial, lifestyle or offsetting health costs.     

Paying the expected externality for a price quote achieves bargaining efficiency

A seller and buyer have reservation prices x and y. Each has a subjective distribution on the other's reservation price. Paying an offer or the expected benefit the other participant receives from his offer induces honest price quotations, hence efficiency: sale iff y> x.