P S Y C H O L O G Y A N D E C O N O M I C S

· · Safety in Markets: An Impossibility Theorem for Dutch Books, 2004, joint with David Laibson.

Abstract: This paper explores the extent to which markets constrain preferences. First, we show that without transaction costs, agents are immune to exploitation in competitive markets. In particular, a sequence of trades leaving any market participant strictly worse off (termed a money losing Dutch book) is generically impossible. When transaction costs exist in the market, Dutch books are plausible only when agents have inaccurate beliefs about their own future behavior. Thus, markets are appropriate filters of non-standard preferences only when sufficient irrational behavioral expectations are allowed. Second, we show that while non-standard preferences may be sustained in competitive markets, they are generically non-identifiable. Under mild conditions, any profile of demands can be explained with a standard, time-consistent, model. Nonetheless, we demonstrate that such a model will have weak predictive power across markets if non-standard preferences indeed prevail.

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· · What’s in a Surname? The Effects of Surname Initials on Academic Success, 2004, joint with Liran Einav.

Abstract: We present evidence that a variety of proxies for success in the U.S. economics labor market (tenure at highly ranked schools, membership in the Econometric Society, and to a lesser extent, Nobel Prize and Clark Medal winnings) are correlated with surname initials, favoring economists with surname initials lower in the alphabet. These patterns persist even when controlling for country of origin, ethnicity, and religion. We suspect that these effects are related to the existing norm in economics prescribing alphabetical ordering of authors' credits. Indeed, there is no significant correlation between surname initials and tenure at departments of psychology, where authors are credited roughly according to their intellectual contribution. The economics market participants seem to react to this phenomenon. Analyzing publications in the top economics journals since 1980, we note two consistent patterns: authors participating in projects with more than three authors have significantly lower surname initials, and authors writing papers in which the order of credits is non-alphabetical have significantly higher surname initials.

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· · Frequent Social Comparisons, Self-Esteem, and Negative Emotions and Behaviors: The Dark Side of Social Comparisons, 2004, joint with Judith White, Ellen Langer, and Johnny Welch, Journal of Adult Development, forthcoming.

Abstract: Social comparisons serve several positive functions, including self-enhancement. Frequent social comparisons, however, have a dark side. Two studies examined the relationship between frequent social comparisons and destructive emotions and behaviors. In Study 1, people who said they made frequent social comparisons were more likely to experience envy, guilt, regret, and to lie, blame others, get defensive, and to have unmet cravings. In Study 2, police officers who said they made frequent social comparisons were more likely show ingroup bias and to be less satisfied with their jobs. The dark side of frequent social comparisons was not associated with self-esteem. Results are discussed in terms of the role individual differences in social comparison processes.

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· · I’ll See It when I’ll Believe It – A Simple Model of Cognitive Consistency, 2002.

Abstract: Psychological experiments demonstrate that people exhibit a taste for consistency. Individuals are inclined to interpret new evidence in ways that confirm their pre-existing beliefs. They also tend to change their beliefs to enhance the desirability of their past actions. I present a model that incorporates these effects into an agent's utility function and allows me to characterize when: 1. agents become under- and over-confident, 2. agents exhibit excess stickiness in action choices, 3. agents prefer less accurate signals, and 4. agents are willing to pay in order to forgo signals altogether. Applications to political campaigns and investment decisions are explored.

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· · Believe and Let Believe: Axiomatic Foundations for Belief Dependent Utility Functionals, 2001.

Abstract: A large body of experimental data demonstrates that people's beliefs influence their well-being beyond the indirect effect through the actions taken. I present a model that incorporates beliefs into an agent's utility function. The paper provides axiomatic foundations for a special class of non-additive utility indices defined over infinite streams of beliefs and actions. I assume that: 1. there exists a (null) belief that does not have any effect on future preferences; 2. the agent has finite memory - only finite histories have an effect on current preferences; and 3. if the agent knows she will not be getting any additional future information, she prefers today's beliefs to be consistent with her past choices. Preferences satisfying these assumptions admit a generalized discounted utility representation in which all terms depend on both actions and beliefs. Experimental testability of the proposed framework is also discussed.

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行为经济学是很新的学科啊！