Our recent working paper (Ambuehl, Ockenfels, and Stewart 2017) shows theoretically and experimentally that people with higher costs of information processing respond more to an increase in the incentive for a complex transaction, and decide to participate based on a worse understanding of its consequences. Here, we address the resulting tradeoff between the principle of informed consent and the principle of free contract. Respondents to our vignette study on oocyte donation overwhelmingly favor the former and support policies that require donors to thoroughly understand the transaction. This finding helps design markets that are not only efficient but also considered ethical.

Participation payments are used in many transactions about which people know little but can learn more: incentives for medical trial participation, signing bonuses for job applicants, or price rebates on consumer durables. Who opts into the transaction when given such incentives? We theoretically and experimentally identify a composition effect whereby incentives disproportionately increase participation among those for whom learning is harder. Moreover, these individuals use less information to decide whether to participate, which makes disappointment more likely. The learning-based composition effect is stronger in settings in which information acquisition is more difficult.

In a series of binary choice problems, we investigate how a chooser's risk taking changes when others share in their personal risk, either equally or unequally. We find that when the safe option yields inequality, the risky option is taken significantly more often. On the other hand, the inequality resulting from the risky choice does not affect risk taking. We also find that choosers tend to be less risk-averse in a one-person context compared to when the risk also affects the payoff of another. (C72, D81, Z13)

Inequality Aversion, Efficiency, and Maximin Preferences in Simple Distribution Experiments: Comment by Gary E. Bolton and Axel Ockenfels. Published in volume 96, issue 5, pages 1906-1911 of American Economic Review, December 2006

Last-Minute Bidding and the Rules for Ending Second-Price Auctions: Evidence from eBay and Amazon Auctions on the Internet by Alvin E. Roth and Axel Ockenfels. Published in volume 92, issue 4, pages 1093-1103 of American Economic Review, September 2002

We demonstrate that a simple model, constructed on the premise that people are motivated by both their pecuniary payoff and their relative payoff standing, organizes a large and seemingly disparate set of laboratory observations as one consistent pattern. The model is incomplete information but nevertheless posed entirely in terms of directly observable variables. The model explains observations from games where equity is thought to be a factor, such as ultimatum and dictator, games where reciprocity is thought to play a role, such as the prisoner's dilemma and gift exchange, and games where competitive behavior is observed, such as Bertrand markets.

We compare evaluations of employee performance by individuals and groups of supervisors, analyzing a formal model and running a laboratory experiment. The model predicts that multirater evaluations are more precise than single-rater evaluations if groups rationally aggregate their signals about employee performance. Our controlled laboratory experiment confirms this prediction and finds evidence that this can indeed be attributed to accurate information processing in the group. Moreover, when employee compensation depends on evaluations, multirater evaluations tend to be associated with higher performance.

We study experimentally when, why, and how people intervene in others’ choices. Choice Architects (CAs) construct opportunity sets containing bundles of time-indexed payments for Choosers. CAs frequently prevent impatient choices despite opportunities to provide advice, believing Choosers benefit. They violate common behavioral welfare criteria by removing impatient options even when all payoffs are delayed. CAs intervene not by removing options they wish they could resist when choosing for themselves (mistakes-projective paternalism), but rather as if they seek to align others’ choices with their own aspirations (ideals-projective paternalism). Laboratory choices predict subjects’ support for actual paternalistic policies.