We investigate how the selection process of a leader affects team performance with respect to social learning. We use a laboratory experiment in which an incentivized guessing task is repeated in a star network with the leader at the center. Leader selection is either based on competence, on self-confidence, or made at random. In our setting, teams with random leaders do not underperform. They even outperform teams with leaders selected on self-confidence. Hence, self-confidence can be a dangerous proxy for competence of a leader. We show that it is the declaration of the selection procedure which makes non-random leaders overly influential. To investigate the opinion dynamics, we set up a horse race between several rational and naïve models of social learning. The prevalent conservatism in updating, together with the strong influence of the team leader, imply an information loss since the other team members’ knowledge is not sufficiently integrated.

We conduct a laboratory experiment in Kenya in which we elicit time and risk preference parameters from 494 participants, using convex time budgets and tightly controlling for transaction costs. Using the Kenyan mobile money system M-Pesa to make real-time transfers to subjects’ phones , we vary whether same-day payments are made immediately after the experimental session or at the close of the business day. We find strong evidence of present bias, with estimates of the present bias parameter ranging from 0.902 to 0.924—but only when same-day payments are made immediately after the experiment.

We implement a laboratory financial market where traders can access costly technology that reduces communication latency with a remote exchange. In this environment, we conduct a market design study on high-frequency trading: we contrast the performance of the newly proposed frequent batch auction (FBA) against the continuous double auction (CDA), which organizes trades in most exchanges worldwide. Our evidence suggests that, relative to the CDA, the FBA exhibits (1) less predatory trading behavior, (2) lower investments in low-latency communication technology, (3) lower transaction costs, and (4) lower volatility in market spreads and liquidity. We also find that transitory shocks in the environment have substantially greater impact on market dynamics in the CDA than in the FBA.

We study gender differences in relation to performance and sabotage in competitions. While we find no systematic gender differences in performance in the real effort task, we observe a strong gender gap in sabotage choices in our experiment. This gap is rooted in the uncertainty about the opponent’s sabotage: in the absence of information about the opponent’s sabotage choice, males expect to suffer from sabotage to a higher degree than females and choose higher sabotage levels themselves. If beliefs are exogenously aligned by implementing sabotage via strategy method, the gender gap in sabotage choices disappears. Moreover, providing a noisy signal about the sabotage level from which subjects might suffer leads to an endogenous alignment of beliefs and eliminates the gender gap in sabotage.

We investigate how information about the preferences of others affects the persistence of ‘bad’ social norms. One view is that bad norms thrive even when people are informed of the preferences of others, since the bad norm is an equilibrium of a coordination game. The other view is based on pluralistic ignorance, in which uncertainty about others’ preferences is crucial. In an experiment, we find clear support for the pluralistic ignorance perspective . In addition, the strength of social interactions is important for a bad norm to persist. These findings help in understanding the causes of such bad norms, and in designing interventions to change them.

There is ample evidence that people differ considerably in their preferences. We identify individual heterogeneity in type and strength of social preferences in a series of binary three-person dictator games. Based on this identification, we analyze response times in another series of games to investigate the cognitive processes of distributional preferences. We find that response time increases with the number of conflicts between individually relevant motives and decreases with the utility difference between choice options. The selfish motive is more intuitive for subjects who are more selfish. Our findings indicate that the sequential sampling process and the intuition of selfishness jointly produce distribution decisions, and provide an explanation for the mixed results on the correlations between response time and prosociality. Our results also show that it is important to take heterogeneity of preferences into account when investigating the cognitive processes of social decision making.

This experiment investigates a stochastic version of the infinitely repeated prisoner’s dilemma. The stochastic element introduces the importance of beliefs about the future for supporting cooperation as well as cooperation and defection on the equilibrium path. There is more cooperation in treatments where beliefs predict cooperation after subjects gain sufficient experience. There is some evidence for cooperation and defection as predicted by equilibrium, but there is stronger evidence for behavior conditioning on past actions that is not consistent with equilibrium play. In particular, subjects continue cooperating even when it is no longer possible in equilibrium for the realized game.

We test the turnout predictions of the canonical costly voting model through a large-scale, real effort experiment. We recruit 1200 participants through Amazon’s Mechanical Turk and employ a $2\times 2$ between subjects design encompassing small ($N=30$) and large ($N=300$) elections, as well as close and lopsided. As predicted, participants with a higher opportunity cost are less likely to vote; turnout rate decreases as the electorate size increases in lopsided elections and increases the closer the election is in large elections. However, in the large lopsided election the majority turns out to vote at a higher rate than the minority. We rationalize these results as the equilibrium outcome of a model in which voters obtain a small non-monetary utility if they vote and their party wins.

This paper examines the effects of alternative assumptions regarding the curvature of utility upon estimated discount rates in experimental data. To do so, it introduces a novel design to elicit time preference building upon a translation of the Holt and Laury method for risk. The results demonstrate that utility elicited directly from choice over time is significantly concave, but far closer to linear than utility elicited under risk. As a result, the effect of adjusting discount rates for this curvature is modest compared to assuming linear utility, and considerably less than when utility from a risk preference task is imposed.

Traders in global markets operate at different local times-of-day. This implies heterogeneity in circadian timing and likely sleepiness or alertness of those traders operating at less or more optimal times of the day, respectively. This, in turn, may lead to differences in both individual-level trader behavior as well as market level outcomes. We examined these factors by administering single-location and global sessions of an online asset market experiment that regularly produces mispricing and valuation bubbles. Global sessions involved real time trades between subjects in New Zealand and the U.S (i.e., “global” markets) with varied local times of day for each location. Individual traders at suboptimal times of day (or, “circadian mismatched” traders) engaged in riskier trading strategies, such as holding shares (the riskier asset) in later trading rounds and mispricing shares to a greater degree. These strategies resulted in lower earnings for circadian mismatched traders, especially in heterogeneous markets that also included traders at more optimal times-of-day. These differences were also reflected in market level outcomes. Markets with higher circadian mismatch heterogeneity across traders were more likely to exhibit longer lasting asset bubbles and greater share turnover volume. Overall, our results draw attention to a unique, but underappreciated, factor present across traders in global market environments, namely, differences in sleepiness across traders. Thus, this study hopes to highlight the role of circadian mismatch in attempting to understand trader behavior and, ultimately, market volatility.

Rationality is a fundamental pillar of Economics. It is however unclear if this assumption holds when decisions are made under stress. To answer this question, we design two laboratory experiments where we exogenously induce physiological stress in participants and test the consistency of their choices with economic rationality. In both experiments we induce stress with the Cold Pressor test and measure economic rationality by the consistency of participants’ choices with the Generalized Axiom of Revealed Preference (GARP). In the first experiment, participants delay the decision-making task for 20 min until the cortisol level peaks. We find significant differences in cortisol levels between the stressed group and the placebo group which, however, do not affect the consistency of choices with GARP. In a second experiment, we study the immediate effect of the stressor on rationality. Overall, results from the second experiment confirm that rationality is not impaired by the stressor. If anything, we observe that compared to the placebo group, participants are more consistent with rationality immediately after the stressor. Our findings provide strong empirical support for the robustness of the economic rationality assumption under physiological stress.

Social media permeates many aspects of our lives, including how we connect with others, where we get our news and how we spend our time. Yet, we know little about the economic effects for users. In 2017, we ran a large field experiment with over 1765 individuals to document the value of Facebook to users and its causal effect on news, well-being and daily activities. Participants reveal how much they value one week of Facebook usage and are then randomly assigned to a validated Facebook restriction or normal use. One week of Facebook is worth $67. Those who are off Facebook for one week reduce news consumption, are less likely to recognize politically-skewed news stories, report being less depressed and engage in healthier activities. These results are strongest for men. Our results further suggest that, after the restriction, Facebook’s value increases, consistent with information loss or that using Facebook may be addictive.