Does choice change preferences? An incentivized test of the mere choice effect.

Unlabelled: Widespread evidence from psychology and neuroscience documents that previous choices unconditionally increase the later desirability of chosen objects, even if those choices were uninformative. This is problematic for economists who use choice data to estimate latent preferences, demand functions, and social welfare. The evidence on this , however, exhibits serious shortcomings which prevent evaluating its possible relevance for economics.

Ethical allocation of scarce vaccine doses: The Priority-Equality protocol.

Background: Whenever vaccines for a new pandemic or widespread epidemic are developed, demand greatly exceeds the available supply of vaccine doses in the crucial, initial phases of vaccination. Rationing protocols must then fulfill a number of ethical principles balancing equal treatment of individuals and prioritization of at-risk and instrumental subpopulations. For COVID-19, actual rationing methods used a territory-based first allocation stage based on proportionality to population size, followed by locally-implemented prioritization rules.

The Role of Payoff Valence on Voting: Egalitarian for Gains and Selfish for Losses.

We study how payoff valence affects voting behavior on the distribution of monetary outcomes framed as gains or losses in a group when using standard voting (PV) procedures and when using voting (AV). The latter method allows the subjects to approve of as many alternatives as they wish and has been shown to eliminate the incentives to vote strategically. For both methods, we observe that voters express higher support for egalitarian allocations (and lower support for selfish options) when sharing gains than when sharing losses.

Generous with individuals and selfish to the masses.

The seemingly rampant economic selfishness suggested by many recent corporate scandals is at odds with empirical results from behavioural economics, which demonstrate high levels of prosocial behaviour in bilateral interactions and low levels of dishonest behaviour. We design an experimental setting, the 'Big Robber' game, where a 'robber' can obtain a large personal gain by appropriating the earnings of a large group of 'victims'. In a large laboratory experiment (N = 640), more than half of all robbers took as much as possible and almost nobody declined to rob.

Conditional valuation for combinations of goods in primates.

Valuing goods and selecting the one with the highest value forms the basis of adaptive behaviour across species. While it is obvious that the valuation of a given type of goods depends on ownership and availability of that type of goods, the effects of other goods on valuation of the original good are sometimes underappreciated. Yet, goods interact with each other, indicating that the valuation of a given good is conditional on the other goods it is combined with, both in the wild and the laboratory.

Trust Games and Beyond.

Trust is fundamental for the stability of human society. A large part of the experimental literature relies on the Trust Game as the workhorse to measure individual differences in trust and trustworthiness. In this review we highlight the difficulties and limitations of this popular paradigm, as well as the relations to alternative instruments ranging from survey measures to neurochemical manipulations and neuroimaging.

True to which self? Lay rationalism and decision satisfaction in self-control conflicts.

Are people more satisfied with decisions to resist or to indulge temptation? We propose that the effect of restraint versus indulgence on decision satisfaction depends on individual differences in lay rationalism, that is, reliance on reason versus feelings to guide decisions. Across 2 pilot studies and 9 main studies (N = 3,264) with different methodologies and various self-control domains, we found consistent evidence that individuals experience higher satisfaction with restraint the more they rely on reason than on feelings. The proposed effect uniquely concerns individual differences in lay rationalism and is independent from individual differences in trait self-control.

Cognitive Reflection, Decision Biases, and Response Times.

We present novel evidence on response times and personality traits in standard questions from the decision-making literature where responses are relatively slow (medians around half a minute or above). To this end, we measured response times in a number of incentivized, framed items (decisions from description) including the Cognitive Reflection Test, two additional questions following the same logic, and a number of classic questions used to study decision biases in probability judgments (base-rate neglect, the conjunction fallacy, and the ratio bias). All questions create a conflict between an intuitive process and more deliberative thinking.

Inertia and Decision Making.

Decision inertia is the tendency to repeat previous choices independently of the outcome, which can give rise to perseveration in suboptimal choices. We investigate this tendency in probability-updating tasks. Study 1 shows that, whenever decision inertia conflicts with normatively optimal behavior (Bayesian updating), error rates are larger and decisions are slower.

Higher incentives can impair performance: neural evidence on reinforcement and rationality.

Standard economic thinking postulates that increased monetary incentives should increase performance. Human decision makers, however, frequently focus on past performance, a form of reinforcement learning occasionally at odds with rational decision making. We used an incentivized belief-updating task from economics to investigate this conflict through measurements of neural correlates of reward processing.

The neural basis of belief updating and rational decision making.

Rational decision making under uncertainty requires forming beliefs that integrate prior and new information through Bayes' rule. Human decision makers typically deviate from Bayesian updating by either overweighting the prior (conservatism) or overweighting new information (e.g.