A fault confessed is half redressed—Confessions and punishment

Confessions after failures are socially desirable. However, confessions also bear the risk of punishment. In a laboratory experiment I examine how confessions work. I analyze whether the willingness to punish harmful failures depends on how the harmed party has learned about the outcome. The harmed party can learn about the outcome via random detection or self-report by the performer. There are two major findings: first, confessions are a powerful instrument: punishment for confessed failures is less likely than for randomly detected failures. Second, confessions are much more likely to occur if there is no punishment.     

Negative recency, randomization device choice, and reduction of compound lotteries

We report an experiment in which subjects are not indifferent between real-money lotteries implemented with randomization devices that are equivalent under the Reduction Axiom. Instead, choice behavior is consistent with subjective distortion of conditional probability, and this persists in treatment conditions that control for (i) computational limitations and (ii) possible confounding by ratio bias.     

Risk taking by agents: The role of ex-ante and ex-post accountability

We study the role of accountability in situations where an agent makes risky decisions for a principal. We observe that in the absence of accountability, agents choose less risk averse investments for the principal than investors who invest for their own account. Accountability mitigates the observed decrease in risk aversion. Differences are observed between situations where agents are accountable for their decision (“ex-ante”) and where they are accountable for the outcome (“ex-post”).     

Search and Knightian uncertainty

Suppose that “uncertainty” about labor market conditions has increased. Does this change induce an unemployed worker to search longer, or shorter? This paper shows that the answer is drastically different depending on whether an increase in “uncertainty” is an increase in risk or that in true uncertainty in the sense of Frank Knight. We show in a general framework that, while an increase in risk (the mean-preserving spread of the wage distribution that the worker thinks she faces) increases the reservation wage, an increase in Knightian uncertainty (a decrease in her confidence about the wage distribution) reduces it.     

Unintended hedging in ambiguity experiments

We describe an ambiguity hedging problem in Ellsberg experiments, where combinations of individually ambiguous bets eliminate aggregate ambiguity, and which may yield incorrect classifications of ambiguity averse subjects. We propose a new classification consistent with this hedging possibility.     

Robustness and ambiguity in continuous time

We use statistical detection theory in a continuous-time environment to provide a new perspective on calibrating a concern about robustness or an aversion to ambiguity. A decision maker repeatedly confronts uncertainty about state transition dynamics and a prior distribution over unobserved states or parameters. Two continuous-time formulations are counterparts of two discrete-time recursive specifications of Hansen and Sargent (2007) [16]. One formulation shares features of the smooth ambiguity model of Klibanoff et al. (2005) and (2009) [24] and [25]. Here our statistical detection calculations guide how to adjust contributions to entropy coming from hidden states as we take a continuous-time limit.     

Sealed bid auctions with ambiguity: Theory and experiments

This study presents a laboratory experiment of the first and second price sealed bid auctions with independent private values, where the distribution of bidder valuations may be unknown. In our experimental setting, in first price auctions, bids are lower with the presence of ambiguity. This result is consistent with ambiguity loving in a model that allows for different ambiguity attitudes. We also find that the first price auction generates significantly higher revenue than the second price auction with and without ambiguity.     

On the impossibility of achieving no regrets in repeated games

Regret-minimizing strategies for repeated games have been receiving increasing attention in the literature. These are simple adaptive behavior rules that lead to no regrets and, if followed by all players, exhibit nice convergence properties: the average play converges to correlated equilibrium, or even to Nash equilibrium in certain classes of games. However, the no-regret property relies on a strong assumption that each player treats her opponents as unresponsive and fully ignores the opponents’ possible reactions to her actions. We show that if at least one player is slightly responsive, it is impossible to achieve no regrets, and convergence results for regret minimization with responsive opponents are unknown.     

Decision time and steps of reasoning in a competitive market entry game

Entry decisions in market entry games usually depend on the belief about how many others are entering the market, the belief about the own rank in a real effort task, and subjects’ risk preferences. In this paper I am able to replicate these basic results and examine two further dimensions: (i) the level of strategic sophistication, which has a positive impact on entry decisions, and (ii) the impact of time pressure, which has a (partly) negative influence on entry rates. Furthermore, when ranks are determined using a real effort task, differences in entry rates are explainable by higher competitiveness of males. Additionally, I show that individual characteristics are more important for the entry decision in more competitive environments.     

Overconfidence as a social bias: Experimental evidence

The overconfidence bias is discussed extensively in economic studies, yet fails to hold experimentally once monetary incentives and feedback are implemented. We consider overconfidence as a social bias. For a simple real effort task, we show that, individually, economic conditions effectively prevent overconfidence. By contrast, the introduction of a very basic, purely observational social setting fosters overconfident self-assessments. Additionally, observing others’ actions effectively eliminates underconfidence compared to the individual setting.     

Incentive effects: The case of belief elicitation from individuals in groups

Non-incentivized belief elicitation has a negative effect on the belief accuracy of experienced observers predicting choices in 2 × 2 matrix games. This negative impact extends to the accuracy of group beliefs and revised beliefs after forecasters know each other's initial beliefs.     

Do bad risks know it? Experimental evidence on optimism and adverse selection

Subjects who overestimate their performance in experimental tasks unrelated to travel are less willing to insure against failing in the task and also less inclined to buy travel insurance. This suggests intrinsic optimism influences insurance demand and diminishes adverse selection.     

Risk attitudes and the stag-hunt game

A stag-hunt game (with the risky and safe actions) has two pure Nash equilibria that are Pareto-rankable. The risky action leads either to the Pareto-superior equilibrium (high payoff) or to out of equilibrium (low payoff) depending on the opponent’s action. Both players may want to obtain high payoff but uncertainty about the opponent’s action may prevent them to take such strategic risk. This paper investigates how information about the risk attitude of an opponent affects a player’s action choice in the stag-hunt game. I find that although a subject’s propensity to choose the risky action depends on her opponent’s risk attitude, it does not depend on her own risk attitude.     

Informational control and organizational design

This paper focuses on issues of allocating authority between an uninformed principal and an informed expert. We analyze the benefits of informational control—restricting the precision of the expert's information (without learning its content). In this case, the result of Dessein (2002) [8] that delegating decisions to a perfectly informed expert is better than communication when preferences between the expert and the principal are not too far apart is reversed. We demonstrate that these organizational forms—informational control and delegation—can be either complements or substitutes, depending on the principal's ability to affect the expert's discretion about the set of allowed policies.     

The Troika paradox

In three binary choice problems, people reveal a choice pattern which falsifies expected utility theory and many generalized non-expected utility theories. This new paradox challenges popular non-expected utility models analogously to how the Allais paradox challenged neoclassical expected utility theory.     

Between-game rule learning in dissimilar symmetric normal-form games

Rule learning posits that decision makers, rather than choosing over actions, choose over behavioral rules with different levels of sophistication. Rules are reinforced over time based on their historically observed payoffs in a given game. Past works on rule learning have shown that when playing a single game over a number of rounds, players can learn to form sophisticated beliefs about others. Here we are interested in learning that occurs between games where the set of actions is not directly comparable from one game to the next. We study a sequence of ten thrice-played dissimilar games. Using experimental data, we find that our rule learning model captures the ability of players to learn to reason across games. However, this learning appears different from within-game rule learning as previously documented. The main adjustment in sophistication occurs by switching from non-belief-based strategies to belief-based strategies. The sophistication of the beliefs themselves increases only slightly over time.     

Good news and bad news in two-armed bandits

This note provides a characterization of optimal policies in a class of two-armed bandits that allows for correlated arms. This characterization extends previously known results in the literature. In particular, it implies, under a mild continuity assumption, the optimality of cutoff belief strategies for this class of bandits. Cutoff beliefs are not unique, though.     

An experimental analysis of the bandit problem

Summary.  We investigate, in an experimental setting, the behavior of single decision makers who at discrete time intervals over an “infinite” horizon may choose one action from a set of possible actions where this set is constant over time, i.e. a bandit problem. Two bandit environments are examined, one in which the predicted behavior should always be myopic (the two-armed bandit) and the other in which the predicted behavior should never be myopic (the one-armed bandit). We also investigate the comparative static predictions as the underlying parameters of the bandit environments are changed. The aggregate results show that the behavior in the two bandit environments are quantitatively different and in the direction of the theoretical predictions. Received: October, 27, 1994; revised version February 27, 1996     

Robust estimation and control under commitment

In a Markov decision problem with hidden state variables, a decision maker expresses fear that his model is misspecified by surrounding it with a set of alternatives that are nearby as measured by their expected log likelihood ratios (entropies). Sets of martingales represent alternative models. Within a two-player zero-sum game under commitment, a minimizing player chooses a martingale at time 0. Probability distributions that solve distorted filtering problems serve as state variables, much like the posterior in problems without concerns about misspecification. We state conditions under which an equilibrium of the zero-sum game with commitment has a recursive representation that can be cast in terms of two risk-sensitivity operators. We apply our results to a linear quadratic example that makes contact with findings of T. Ba?ar and P. Bernhard [H^∞-Optimal Control and Related Minimax Design Problems, second ed., Birkhauser, Basel, 1995] and P. Whittle [Risk-sensitive Optimal Control, Wiley, New York, 1990].     

HIV testing,subjective beliefs and economic behavior

This paper examines the effects of learning HIV status on economic behavior among rural Malawians. According to economic life-cycle models, if learning HIV results is informative about additional years of life, being diagnosed HIV-positive or negative should predict changes in consumption, investment and savings behavior with important micro and macro-economic implications. Using an experiment that randomly assigned incentives to learn HIV results, I find that while learning HIV results had short term effects on subjective belief of HIV infection, these differences did not persist after two years. Consistent with this, there were relatively few differences two years later in savings, income, expenditures, and employment between those who learned and did not learn their status.